Part I. Logic

LOGIC

Logic is defined by Gassendi as the science of intellect ‘qua veri sequax.’ Its rules, being general, conduct to all knowledge, not merely the knowledge of nature, but knowledge of every description. The term Logic Gassendi connects with Logos, which denotes the inner conversation of the mind, of which Ratio is a species.

Logic, then, in the first instance is the science of all mental operations that are in any sense organised. This science may be Dialectic, Organic, or, thirdly, Logic in the narrower sense. Logic in the widest sense is ars cogitandi; as Dialectic it is ars disserendi; as Organic it is ars dirigendi actiones mentis: while the ars Logica in the narrower sense is canonica or ars veri et falsi diiudicandi. This second use of the term Logic is confined to the ars bene cogitandi, which is held to be different from the ars cogitandi, and identical with the ars ratiocinandi. This is the real Logic as usually understood, and the branch that demands our serious attention. Bene cogitare comprises bene imaginari, proponere, colligere et ordinare: and in accord with these our Logic will comprise the subjects of Imagination, Proposition, Syllogism, and Method.

The action denoted by the verb ‘imaginari’ is that of forming an idea, also called species, notio, praenotio, anticipatio, or conceptus. The ideas present themselves to the mind as soon as the object is named, and we, as it were, see right into them. This intuitive perception we call simple imagination, because it is limited to the mere image of the thing without affirmation or negation. The idea is identical with the phantasma. The proposition is an enunciative judgment: colligere denotes the illative judgment; while the correct treatment of a number of judgments in related syllogisms constitutes the ars bene ordinandi.

II.

Logic is in the first instance Natural. Men had thoughts before they evolved any method of thinking, and probably even in the earliest times there was some method of thought even if there was no thought of method. The serpent in the garden of Eden doubtless used subtle arguments; but these primary forms of Logic are of no serious importance: we may therefore pass them over, and confine our attention to Artificial Logic.

The earliest Logic in the proper sense is that of Epicurus. Zeno’s Logic was purely eristic, and a non-syllogistic method. Epicurus has been accused of despising Logic, but it was really only the Logic of the Stoics which he rejected. When he dropped the term Logic for the name ‘canons’ it was only the name that he really changed: ‘nomen rejecit rem retinuit’ [I. 52].

All questions, said Epicurus, are either about things or words. When the question is about things a criterion of Judgment is required. Things may be classified as (a) naturales and (b) morales. In the case of res naturales, we require sense and mind: for res morales appetitus is required. As there are three faculties, namely sense, mind, and feeling, we have three criteria, namely sensation, anticipation, and passion.

The term sense denotes both the faculty and the function: as a criterion it denotes the function primarily, for we judge by the perception of the senses. The anticipatio is the image stored in the mind; the passio is the pleasure or pain which controls choice. These will be better understood if we quote the canons.

CANON i. Sensus nunquam fallitur: ac proinde est omnis sensio omnisque Phantasiae seu apparentiae perceptio vera.

CANON ii. Opinio est consequens sensum sensionique superadjecta in quam Veritas aut falsitas cadit.

CANON iii. Opinio illa vera est cui vel suffragatur vel non refragatur sensus evidentia.

CANON iv. Opinio illa falsa est cui vel refragatur vel non suffragatur sensus evidentia.

CANON v. Omnis quae in mente est anticipatio seu praenotio dependet a sensibus: idque vel incursione, vel proportione, vel similitudine vel compositione.

CANON vi. Anticipatio est ipsa rei notio sive definitio, sine qua quidquam quaerere, dubitare, opinari, imo et nominari non licet.

CANON vii. Est anticipatio in omni Ratiocinatione principium, quasi nempe id ad quod attendentes inferimus unum esse idem aut diversum, conjunctum aut disjunctum.

CANON viii. Quod inevidens est ex rei evidentis anticipatione demonstrari debet.

These eight canons are the basis of the theory of knowledge, in so far as one is given us. We start with a blank mind capable of bare sensation: the evidence of sense is one against which there is no appeal. In the fifth canon we have some new terms: ‘incursio’ denotes the entrance of an idea as such: proportio is the creation of an idea, e.g. of a giant, by extending the idea of a man; similitudo is construction of an object not seen by analogy with one we know; lastly, compositio is the voluntary union of ideas such as we perform in constructing the notion of the centaur. In the sixth canon the phrase ‘notio sive definitio’ covers two aspects of the anticipatio. As a mental image the anticipatio is that visualizing of an object which we perform when we hear a name significant to us. This not being the product of a present object, is producible at will and is that which we recall and mentally survey in framing a definition. A verbal definition is a secondary product and not necessary except for one desiring to communicate his ideas. The essential thing is a formal notion or a notion described and accurately delimited; and this is what Gassendi really wants.

III.

The remaining canons, ix. to xiv., are rules for practical choice and clear speaking. Upon these there follow summaries of the works of Lully, Ramus, and Bacon.

The second book opens with the question of the nature of that Truth which is considered to be the end of Logic.

Truth is for Logic an end which is external to it. The internal end for Logic is right thinking; but right thoughts are higher and better than this: Logic prepares the mind, and the end of this preparation is attained in applied thought. The common distinction made between ‘logica docens’ and ‘logica utens’ expresses this point. The former is abjuncta a rebus, the latter conjuncta cum rebus. It is only the latter, the concrete applied logic, that concerns us at present. The Truth whose nature we are pursuing is truth of judgment. There is a truth of existence expressed in the formula ‘everything is what it is’; Gassendi recognises that reality must always be real, and a picture is not primarily ‘falsus homo’ but ‘vera effigies’; on the other hand, he clearly does not suspect that the existence of which he predicates truth is always a being for mind. To Being as it is for thought belongs another kind of truth, truth of judgment, which is the agreement of judgment with fact.

Gassendi is now grappling with a difficult subject, and allowance must be made for the crudeness of the position on account of its novelty. Gassendi’s aim is to reach a common-sense position. It appears to him that everything is what it is in itself: like all other defenders of this point he goes upon the tacit assumption that the phrase ‘a thing is what it is’ means a thing is for itself what it is for consciousness. As yet the animistic vein is not quite explicitly eliminated from the world of nature as we know it: the object is not properly conceived as always relative to mind; still less is the object as related to mind expressly distinguished from the thing as a further ultimate reality. But with all its crudity the theory of Gassendi commands respect as a straightforward treatment of the world of daily life. The primary dogma that ‘everything is what it is’ is supplemented by the notion that sense shows us everything as it is. There is therefore no thought of the bodily medium being itself the destroyer of all knowledge: the immediate relation is the psychic atom out of which the fabric of knowledge is built, and is itself irresolvable and wholly real. Immediate relations are, however, not always possible. Things are not all of the same kind. Some are ‘manifestae,’ and with them we have no trouble; others are ‘occultae,’ either ‘penitus,’ ‘natura,’ or ‘ad tempus.’ The first are hopeless: the last may be left for Time to reveal: the second form the sphere which it pays us to further examine. It follows from this division that there is an unknowable; but that which is unknown is so by reason of its own nature, not by reason of any defect in us. The example given is the knowledge that the stars are even in number: the unknown is in this case the answer to a problem, and the knowledge that there is an answer depends on a disjunctive judgment, ‘stars are either odd or even.’ It would seem as though, if this is the type of the unknowable, the unknowable ‘penitus’ is always a case of the ‘unknown ad tempus.’ The ‘res occultae natura’ are those which can be reached by inference: as, for example, the existence of pores in an apparently continuous surface deduced from the excretion of sweat. To reach these truths which lie below the surface we require a criterion, or instrument.

Properly a criterion is a standard of judgment, as Gassendi recognises, but it is also employed in the sense of instrument. He divides criteria into (1) those by which we live, and (2) those by which we learn. The former are standards, such as ‘lex patriae,’ ‘consuetudo,’ and the like, together with the moral tests of Epicurus, pain and pleasure. These do not really belong to Logic, which is concerned with the second class. This is subdivided into (a) mechanical, and (b) natural criteria. The former subdivision includes the foot-rule and instruments of that kind; the latter contains ‘id per quod’ and ‘id secundum quod,’ namely the faculty and the function of the faculty. Some add to these a third, ‘a quo,’ and define it as the mind. But while for ascertaining the weight of a thing we require the scales, the poising of the scales, and the man to record the result, and also for knowledge we require the sense, the function of the sense, and the mind that knows the result, the third is in both cases not a criterion, but a judge.

IV.

Now that we have determined the nature of the world we confront and the criteria available for its discovery, we must explore the question of the possibility of knowledge, for that has been more than once denied.

The Sceptics assert that man knows nothing in the sense that he cannot penetrate into the inner beings of things. The Dogmatists, on the other hand, declare the criteria of sense and intellect to be absolute: everything can be known through them. Both the schools err from excess, and the truth lies in the golden mean: some things are known, and truly known, while others are obscure and do not admit of more than probability. Truth must be regarded as always possible, but not always actual: what we do know is truth, but at the same time we cannot be said to know all truth.

A difficulty arises here which Gassendi does not seem to suspect. If we do not know all that might be known, how does the ignorance arise, and how is the present knowledge affected by the absence of further knowledge? Moreover, what do we require to make our knowledge more complete? Is it more system or more senses? Clearly if the whole is regarded as a growing system, it is difficult to avoid the conclusion that no one stage is in itself finally true. On the other hand, if we imagine that the world around us contains forces which appeal to us in vain because we have no senses that can respond to them, knowledge is bound to remain cramped and imperfect for all time. The atomism of Gassendi’s standpoint now becomes obvious. He thinks that a piece of the truth is at least truth. The system of truths, then, only differs from the individual truths in respect of quantity. This point can be made clearer when we have further considered the nature of knowledge.

In opposition to Gorgias, Gassendi asserts that there must be something and some truth. Appearances are admitted to be true: it is the occult truths which give rise to doubt. To penetrate into the occult truth we must advance by means of the known to the unknown. A fact which is known and used as the key to further knowledge is called ‘signum, medium, seu argumentum.’ For example, in the sentence ‘if the sun shines it is day,’ the signum is ‘if the sun shines.’ Following Aristotle and Quintilian, we divide the signa into (1) necessary and (2) probable. The necessary signa are either (a) indicativa or (b) commonefactiva. When the signa are indicativa they prove the existence of the occult reality, as, for example, when sweat is taken as a proof that pores exist in the skin. The commonefactiva belong to the class of ‘res ad tempus occultae.’ In this case both the objects concerned are possible objects of experience. When a man sees smoke he infers the presence of fire, and can proceed to verify this by actual experience. It is not this but the former case that the sceptics attack. The formula for this is, ‘If A is not, then B is not’: hence given B, A must be posited. The question therefore amounts to this: can we have a perception that is not a sense-perception, and none the less true? Gassendi thinks that we can. The signum is a sense-datum, and must be given first; but it has value only for a mind that perceives and grasps it, so much so that the mind is justified in revising and correcting its sense-impressions. The position of the Sceptics that experiences differ and there is no universal truth is refuted by the facts. For the experiences may differ, but in recognising the differences we practically admit that there are two fixed points, namely, the cause and the disposition of the organism which is affected. As knowledge is a relation the nature of the relation may vary, and this may lead to partial and confusing statements. We say ‘the sun melts the wax’: we cannot say that the sun is in its own nature ‘melting,’ any more than that it is ‘hardening’ when it hardens the mud. The underlying fact is that it radiates heat, which softens some bodies and hardens others according to their dispositions. Our limits are given at one end by the immediate certainty of sense, and at the other by the ‘indubitata principia’ of mind. It follows that single facts and true propositions are alike self-evident. If the intellect makes errors it also corrects them, and knows the pure truth of axioms.

The critical point of this logic is the determination of the relation of reason to sense. At first it looks as though this was a theory purely sensualistic, but the modifications introduced finally reverse that judgment. Gassendi’s real meaning appears to be that experience gives us all we know; we may get out of experience much that is not apparent to the senses, but we must never suppose that we can by ourselves make experience: knowledge is a relation, and therefore a pure creative activity of mind is a sheer impossibility. Gassendi does not say that the mind cannot know much that the senses never reveal, or that we cannot confront experience with concepts derived from reflection: all he says is that however far we travel from the sources, there can be no truth or reality in thoughts that cannot be brought back to their contact with experience. Psychologically this is expressed by saying that the intellect is a supersensuous agent, which is in fact always allied to a sensuous organism.

Gassendi thought Bacon and Descartes were both extremists. Bacon confined himself too much to the ars bene colligendi; his condemnation of the syllogism was wrong, ‘cum in syllogismo sit re ipsa robur nervusque omnis ratiocinii’: the syllogism is only a failure because our universal is generally formed ‘ex propositionibus non satis perspectis.’ Descartes, on the other hand, inclined to weave experience out of his inner consciousness, to cultivate the ars bene imaginandi without due regard to the material (auxilia ad habendum veram germanamque rerum notitiam, non tam ab ipsismet per se ac in se explorandis rebus, quam a solo, ipsoque a suis dumtaxat cogitatis pendente Intellectu procedendum existimat, I. 90). This definite expression of opinion makes it clear that Gassendi was steering a middle course between contemporary forms of empiricism and rationalism (v. p. 134).

Gassendi has now finished defining his position with regard to the relation of the mind to its world. The position is obviously modelled on Aristotle, and as was noticed above, is in a sense atomistic. A very significant remark is to be found in the answer to the Sceptics, who argued that, if a thing appears differently to different people, no one appearance can be called the truth. Gassendi says that the truth lies not in the appearance but in the appearing.

Suppose an object appears to me to be of a certain colour, I cannot say that this is ‘ipsissima qualitas quae sit in objecto,’ but I can say that this is the affection due to this object, or this is the relation which this object realises with me. The statement that the object is not red to you cannot make it cease to be red to me, while, on the other hand, the fact that it is not to you what it is to me, proves that it is what it is, for if there were no objective reality the fact of difference could not be explained at all. This view logically implies that the object is essentially what it does, or in other words, it is a ‘possibility of action.’

Atomism necessitates the recognition of the ‘thing’ as a solid unchanging occupant of space. Whether it naturally leads to the rejection of the category of substance for that of function, to the change of the formula of the thing from what it is to what it does, is a question that confronts us vaguely, but with promise of growing clearness.

The Logic proper of Gassendi is divided into four parts, and exhibited in the form of canons. The parts deal with the idea, the proposition, the syllogism, and method respectively.

The primary activity of the conscious being is Imagination, or the reception of an image also called idea. The idea is defined as the object of the mind when it thinks (quae nobis rem quampiam cogitantibus menti obversatur). All ideas come to us from the senses, and we must endorse the saying: nihil in Intellectu quod non prius fuerit in sensu (Canon iv.). These ideas are supplemented by those which the mind constructs by its own activities. From the activity of the mind we derive general ideas. Both singular and general ideas are ‘perfect’ in proportion as they accurately represent the object, and accuracy is obtained by discriminating all the parts of the object, singular or general. So Gassendi praises Anatomy, Chemistry, and all analytical sciences as leading to accurate knowledge of particular objects. In the case of the general idea, he says it is more perfect according as it contains more distinct classes. The general idea of man, for example, is more perfect if it contains not only Europeans, Africans, and Asiatics, but also Americans. It is difficult, he says, to get the idea free from particular distinctions, but it can be done. The reader of Canon viii. will find it difficult to say whether Gassendi’s universal is to contain all particular distinctions or be formed by neglecting them. Man, as a general idea, must be ‘omnibus discriminibus absolutum,’ but at the same time the universal concept cannot be gained by abstraction based on one individual, but results from that process of explicating the essential, which is grounded in the interaction of many particular ideas.

The Proposition is a union of ideas, and forms the second stage of logical process. It is true when the union it affirms is in agreement with objective reality. The objective relation is that of substance and attributes, and the Proposition unites substance and attributes. As the union objectively considered is sometimes necessary and sometimes contingent, so the judgment contained in the proposition is sometimes necessary (the opposite term being “impossible”), sometimes probable.

The syllogism is a nexus of propositions, and is treated by Gassendi in the ordinary formal way. Method is three-fold: of invention, of judgment, and of doctrine. The method of discovery is either analytic or synthetic. It consists essentially in tracking down a middle term or connecting link. Suppose one is required to prove that man is a substance. Taking the subject man we may analyse it and show that it contains the notion of substance: or taking substance we may qualify it (synthetically) until we get that qualification which is identical with man. The process is obviously a resolution of the equation, ‘Man = a substance,’ in the form:

Man = rational living thing. Some substance = rational living thing. Man = some substance.

Gassendi’s preference for mathematical methods would have been quite obvious without his particular reference to geometry.

The method of judgment is likened to proof in arithmetic when we combine addition with subtraction, and use them alternately to prove a result. The final verification is found in the criteria of sense and judgment in which we must finally fix our faith.

The method of doctrine or teaching ‘begins with resolution, and proceeds by composition’ (Canon v.). This is the method of all sciences, physical, mental, and moral. In addition to this simple rule Gassendi preaches clearness of language, clearness of division, avoidance of useless digressions, and the necessity of proceeding from the most common and essential elements to the more obscure.