# Philosophical Works of the Late James Frederick Ferrier/Institutes of Metaphysic (1875)/Section 1/Proposition 16

The Institutes of Metaphysic, Philosophical Works of the Late James Frederick Ferrier (1875 ed., Vol. 1). (E. L. Lushington, & A. Grant, Eds.) Edinburgh: William Blackwood and Sons. pp. 328-334.
PROPOSITION XVI.
THE SUBSTANTIAL IN COGNITION.
DEMONSTRATION.
The first premiss fixes the definition of known substance: "Whatever can be known without anything else being, of necessity, known along with it, is a known substance." But some such thing must be known, otherwise all knowledge would be impossible; because it is obvious that no knowledge could ever take place, if, in order to know a thing, we always required to know something else, and if, in order to know the thing and the something else, we again required to know something else, and so on in infinitum. Under such an interminable process knowledge could never arise. But knowledge does arise. Therefore a point must be reached at which something is known without anything else being, of ​necessity, known along with it. And this something, whatever it may turn out to be, is known substance, according to the definition. Therefore there is a substantial in cognition; in other words, substance is knowable, and is known by us.
OBSERVATIONS AND EXPLANATIONS.
This proposition proves nothing as to existing substance.1. The words "known" and "in cognition" are here inserted (as on other occasions) in order to guard against the supposition that this definition fixes anything, or that this proposition proves anything, in regard to existing substance. Known substance may subsequently turn out to be coincident with existing substance; but this is not to be assumed, and it is not assumed at this place. All that is defined is known substance, and all that is proved is that there is a known substance, not that known substance is existing substance.
Neither does it declare the nature of known substance.2. The reader is also requested to bear in mind that this proposition says nothing as to what known substance is; it merely states and proves that there is such a thing. What the thing is—in other words, what corresponds to the definition—is declared in the next proposition. This remark is made lest any perplexity or dissatisfaction should be occasioned by the vagueness which necessarily hangs over a statement which merely announces that a certain thing ​is, without announcing what it is. This vagueness of statement must communicate a corresponding vagueness of thought to the reader's mind; and he may be uncertain whether he has apprehended the whole meaning of the proposition. He has apprehended its full meaning if he will take it literally as it stands, and be pleased to wait for further light as to what the substantial in cognition is until he comes to Proposition XVII.
Reasons for introducing this proposition.3. The theory of knowing would be very incomplete unless it embraced an explanation of certain words in connection with which the utmost laxity of thought has at all times prevailed, and around which the most confused and fruitless controversies have perpetually revolved. Such words are "substance," "phenomenon," "the absolute," "the relative." The loose and erroneous thinking which is attached to these terms, both in the popular mind and in psychological science, is what lies beyond all the powers of description to exaggerate. Definite articles, therefore, settling their meaning exactly, are quite indispensable in a work which professes to lay down the institutes of all metaphysical thinking, and to supply the standards by a reference to which all vagrant cogitation may be at once pulled up, and all controversies cut short. These articles, moreover, are necessary steps in the inquiry, because its ultimate aim is to ascertain whether, and how far, ​the substantial and the phenomenal, the absolute and the relative, in cognition, equate with the substantial and the phenomenal, the absolute and the relative, in existence.
The position of natural thinking in regard to this proposition. 4. From what has been said, it will be obvious that the question which this proposition answers is simply this: Is there any such thing as known substance?—a point which it is of the utmost importance to determine, the definition of known substance being at the same time given. And the answer which the proposition returns to this question is the affirmative—yes. Now it is remarkable that ordinary thinking also answers this question in the affirmative; and therefore, in so far as ordinary thinking is concerned, there is no counter-proposition, and, consequently, the natural opinion on this point stands in no need of correction. The contradictory inadvertency of natural thinking only comes to light when it condescends upon what known substance is. Vulgar opinion concedes that there are known substances; and so far vulgar opinion is exempt from error. But ask vulgar opinion what known substance is, and vulgar opinion is instantly at fault. It declares that logs of wood and brickbats, and articles of that description, are known substances. Such a statement is contradictory; because known substance, according to the definition, is that, and only that which can be known or thought of ​without anything else being known or thought of along with it. But logs of wood or brickbats cannot be thus known or thought of (as will appear from Prop. XVII., if it is not already evident to the Nader); and therefore the assertion which declares that these, and such things, are known substance, is false and contradictory. But still, in so far as the present proposition is concerned, it encounters no opposition from popular opinion; and therefore to this extent our natural modes of thought are neither inadvertent nor erroneous. To find the exact counter-proposition which Proposition XVI. subverts, we must look to the deliverances of psychology.
Sixteenth counter-proposition.5. Sixteenth Counter-proposition.—"There is," says psychology, "no substantial in cognition; we are not competent to know or to form any conception of substance." Psychology then adds, somewhat inconsistently, that substance is to be conceived as the occult substratum of manifest qualities, the unknown support of known accidents. But inasmuch as we are not considering at present what the nature of substance is, but only the state of the fact as to our knowledge of it, all remarks on this latter part of the psychological doctrine must be reserved for a subsequent occasion (see Prop. XVII., Obs. 8, 9, 10.)
6. This counter-proposition contradicts reason, because it advances a doctrine which, if true, would ​Its downfall.render all cognition impossible. Unless the mind could know something without knowing anything more—in other words, unless it could know substance (for known substance, according to the definition, is whatever can be known without anything more being known), no knowledge, as has been stated in the demonstration, could arise; because, in that case, the mind, before it could know anything, would be eternally under the necessity of knowing something more; and this process never coming to an end, knowledge could never come to a beginning. But knowledge does come to a beginning; it takes place. Therefore the mind can know something without knowing anything besides; or, more shortly, it is cognisant of substance; and the counter-proposition which denies this truth can no more keep its ground against these considerations, than a soap-bubble can withstand a thunderbolt.
Defence of definition of known substance.7. A moderate degree of reflection may convince any one that the definition of known substance here presented, is the only true and tenable and intelligible definition of it which can be formed. No other conception of known or knowable substance can be formed than that it is that which can subsist in thought without anything else subsisting in thought along with it. Whatever can thus stand or subsist is certainly a known substance—a conceived subsistence; whether it be an existing ​substance is a totally different question, and one with which, as has been said again and again, we have at present no concern. A very distinct meaning can be attached to the word substance when thus understood; but every attempt to understand it in any other sense, is sure to result in understanding it in no sense at all.
This definition is due to Spinoza.8. Any further notices, critical or historical, respecting substance, will come in more appropriately under the next proposition. Meanwhile, this may be remarked, that the definition of it here laid down is due to Spinoza, who thus defines substance: "Per substantiam intelligo id, quod in se est, et per se concipitur; hoc est, id cujus conceptus non indiget conceptu alterius rei, a quo formari debeat"—that is, "By substance I understand that which is conceived as standing alone and unattached; in other words, substance is that whose conception does not require to be assisted or supplemented by the conception of anything else." This translation is not strictly literal, but it gives Spinoza's meaning with the utmost exactitude, and more intelligibly than any closer verbal rendering could do. Spinoza's mistake lay in his prematurely giving out this proposition as the definition of existing, and not simply as the definition of known, substance.