Nouns express only abstract ideas of attribution or of relation; and they always imply classification in their meaning, as to name a thing or apply any term as a predicate is an act of abstraction which pre-supposes classification.

§ 5. ORIGIN AND CHARACTER OF PHYSIOLOGICAL KNOWLEDGE.

Thoughts cannot be known by direct propagation from mind to mind, though they may be communicated by means of language; the mental subject, receiving the symbols which transmit the ideas, assimilates them with the ideal signs which represent them in the mind, and which in the ordinary form of transmitting ideas are words. Thus language is the progressive necessity of the mind as food is the conservative necessity of the body, and that sublime necessity of thought yielding supersensual fruit in the field of the ideas is the essential means of elevating us to the rank of rational beings.

In language there are two kinds of expression : intuitions (perceptions which are only felt), and propositions (perceptions which are thought, either inferred or calculated). Language is called propositional when it enunciates some new order of ideas by which we can acquire some knowledge not already experienced. A proposition, in order to be understood, presupposes that the abstract ideas which compose it are already known; and such ideas may be either intrinsic, that is, of self-consciousness (intuitions), or extrinsic ideas which have been previously discovered by means of the senses (sensual representations).

According to the theory of knowledge, the correlative

succession in the acquisition of ideas is as follows: in the first place we get the predicates of attribution (ideas of substance and activity), whose aim is to reach qualitative inductions by comparisons among the qualities of the sensations; we afterwards reflect on the similarity and difference of attributive ideas in order to form the predicates of quantitative relation (ideas of space and time) whose aim is to know with the help of the axioms of Mathematics the comparison of the quantity of the sensations which are perceptible, not directly in matter, but in its mental representations. The ultimate inductions and true axioms once known, we may derive from them the other ideas combined with new sensations, following the rules of deductive logic and mathematical calculation; thus we get the deductions.

The universal act of knowledge is expressed by judgment which consists in the comparison of many concepts with the assertion of their equality or difference. But certain ideas of sensation in reference to the concepts which are compared must necessarily precede the judgment; and besides, it is necessary for the expression of knowledge that the mind should abstract from the judgment of particular cases some unity of thought, some analogy among them which is called the universal meaning; such universal ideas or common abstractions are a necessity for language, and for this reason the rational mind has an imperious tendency to ideal abstractions or generalizations, as the ovule has the tendency to nourish and reproduce. So we see that when many experiences have an element of common sensation, the mind has the condition required for abstraction, in order thereby to form a unity of thought with all similar sensations, and to appropriate this as a basis for the

classification of ideas. Such a universal element cannot be known by any particular or direct experience; the formation of universal concepts is a constructive action-an assimilation of ideas by which these are converted into a product identical not with the sensations but with the mind itself, as the cellule transforms that which it assimilates into an organization similar to itself; and such mental products, called universal ideas, are not simply a sum but a multiplication in which there is a true generation of knowledge.

Thought, we have seen, is of two orders—spontaneous or automatic, and reflexive or voluntary; the first supplies the ideas necessarily acquired by unconscious activity which is inherent in the mind itself; the second makes thought by reflection a self-director with self-consciousness. Spontaneous thought, which is immediate or irreflexive, acquires the knowledge of things according as they are perceived by the senses, and ordinary language expresses such a form of thought. But cosmos thus explained will be known only vaguely and with inexactitude as it appears to our senses. For this reason reflexive thought, which is mediate or philosophical, must, in the domain of science, completely abandon the classification of immediate sensation, and for this purpose ordinary terminology must be changed, or at least fixed, in order to give clear, adequate, and exact symbols to scientific ideas.

No theory can be the fruit of intuition-it is the fruit of thought; and a physiological theory must not be invented by imagination, but planned by quantitative reasonings or calculations which are the fruit of If the mind had only its capacity of sensation,

reason.

even having the capacity of forming direct judgments, it could not follow discourse; and with sensation alone we could not even refer the impressions to the objects which produce them. Objective perceptions are the data for the knowledge of cosmos, but our ideas of the world are conceptual abstractions, which the mind. forms by reasoning.

The interaction of matter and mind may produce either subjective differences-qualitative ideas, or objective differences-quantitative ideas of space and time. The subject (mind) is known by qualities or attributive differences alone, and not by quantitative differences; the object, on the contrary, is known by quantitative differences or different relations, and not by qualitative differences either of substance or activity; that is, objective perceptions which are the first data for the knowledge of Cosmos or ideas of the world are formed by mental abstractions from sensations whose differences are only in quantity. Thus matter and mind (object and subject) can only be known by their reciprocal action (interaction); there is no state of consciousness regarding the knowledge of matter in particular, which is not determined by such mutual action. Now, if we think that objective knowledge that of material nature) is valid, we must also admit that there is a fixed relation among its antecedents; and the sensations which result from the interaction of things and mental activity, must produce the same perception when the extrinsic excitation is the same. Physiological knowledge is based or founded in the perception of mutual actions among objects, that is, in their relations, because all the properties of an object are finally reduced to the condition of producing effects

by interaction among things, and such effects, in order to determine sensations, must produce some change in the organs of sense, manifesting themselves to the mind after their propagation through the nervous conductors and centres. A thing alone cannot be known or conceived, because its existence would not be the object of sensation or of representation in thought. A thing really objective, then, is a term in an infinite series of things which are in mutual dependence, as without this there can be no possible form of reality known, either by experience or by pure thought. Accordingly, those cosmical determinations, which are generally called qualitative, because they cannot be numerically determined, are as quantitative as those which can be numerically determined. Quality directly results from the mutual action between the objects and the mind by an immediate connection without reflection -irreflexive perception, or attribution; and quantity is a relation, either numerical or of extension, among terms by mediate or reflexive connection-reflexive perception or relation properly so-called. There is nothing then truly attributive in objects, as the attribution or difference of quality is purely subjective or mental; while objective differences, on the contrary, depend on quantity, and are material or mechanical relations. Let us now fix well in the mind the idea that determinations of quantity only, such as physiological inquiries, can be derived one from another in accordance with general relations which are called laws. Scientific judgment manifests some fact or syntheses of facts of the universal system, and we learn such facts and syntheses by the concourse of three kinds of ideas, namely, intrinsic intuition, experience,