higher notion is found in the lower; consequently 2. The name of the higher may always be applied to the lower. Thus man may be called an animal, because the marks of life and sensation which distinguish animals are found in him. 3. The higher notion (genus) includes the lower notion (species) with other species, and is therefore of wider extension than it. But the species implies more marks- has a fuller definition—than the genus; and is said, therefore, to be of deeper intension than it. 4. That set of marks which distinguishes any species from the other species in the same genus is called its Specific Difference. 5. The whole nature of a species is ascertained, and its definition given, when the properties of the genus and those which make the specific difference are brought together. 6. We ascend from lower conceptions to higher by throwing away specific differences, i. e. by abstraction. We descend to lower ones by resuming the marks we have thrown away, i.e. by determination. 7. In a system of subordinate genera each must contain the individuals included in the lowest. 8. Co-ordinate species cannot contain the same individuals. 9. The conception of an object consists of the aggregate of its marks, with the notion of existence superadded. 10. Singular objects are invariably referred to and viewed. through general conceptions. 11. A conception is complete and adequate, when it can be resolved at

pleasure into its implied marks by definition, and into its contained species by division. 12. Two marks which stand to each other as positive and privative, like wise and unwise, are called contradictory, because it would be a contradiction in terms to assign them at the same time to the same object. Two marks are called contrary, when it is known a posteriori by experience, and not a priori by the very form of expression, that they cannot belong to the same object, as wise and wicked, warm and frozen.

Οὐδεμίαν γὰρ οὔτε οὕτως οὔτ ̓ ἐκείνως πρᾶξιν οὐδ ̓ ἀπραξίαν δηλοῖ τὰ φωνηθέντα,

τοὶν ἄν τις τοῖς ὀνόμασι τὰ ῥήματα κεράσῃ.-PLATO.

VERY act of judgment is an attempt to reduce to unity two cognitions. When one decides that "Socrates is wise," it is that hereafter one may, by combining the two notions, think of "the wise Socrates." Again, when one decides that "the world is not eternal," it is that hereafter one may refrain from combining the two notions as "the eternal world."

A Judgment then is an expression that two notions can or cannot be reconciled-that the marks of the one may or may not be henceforward assigned to the other. A proposition is the expression of a judgment in words.

*

* This definition is rejected by Mr. Mill, Logic, vol. i. p. 116. seq. on the ground that a judgment expresses the agreement of things rather than of notions. But the notions are controlled by the things, otherwise assent and dissent would be arbitrary. I am forced to say "the day is fine" when the sky is cloudless, because my perceptions must correspond with the facts. This correspondence then the definition in the text is considered to