As first principles of necessary truth he cites, besides the axioms of logic and mathematics, grammatical, aesthetic, moral, and metaphysical principles (among the last belong the principles: "That the qualities which we perceive by our senses must have a subject, which we call body, and that the thoughts we are conscious of must have a subject, which we call mind"; "that whatever begins to exist, must have a cause which produced it").

But with the transfer of these ideas to France, the wall of separation is broken down between the theory of knowledge and the theory of ethics, between natural philosophy and the philosophy of religion; sensationalism forces its way from the region of theory into the sphere of practice, and the mechanical theory is transformed from a principal of physical interpretation into a metaphysical view of the world of an atheistical character.

In the third place it is self-contradictory, for after theology has removed the Deity as far away from man as possible, by means of the negative metaphysical predicates, it finds itself necessitated to bring the two together again through the moral attributeswhich are neither compatible with one another nor with the meta-physicaland crowns the absurdity by the assurance that we can please God by believing that which is incomprehensible.

In our account of the philosophy of Leibnitz we begin with the fundamental metaphysical concepts, pass next to his theory of living beings and of man (theory of knowledge and ethics), and close with his inquiries into the philosophy of religion.

Physical points, the atoms, are physical, but not points; mathematical points are indivisible, but not real; metaphysical or substantial points, the incorporeal, soul-like units, alone combine in themselves indivisibility and realitythe monads are the true atoms.

[Footnote 1: In regard to the dependence of the world on God, there is a certain conflict noticeable in Leibnitz between the metaphysical interests involved in the substantiality of individual beings, together with the moral interests involved in guarding against fatalism, and the opposing interests of religion.

The principium rationis sufficientis governs our empirical knowledge of contingent truths or truths of fact, while, on the other hand, the pure rational knowledge of necessary or eternal (mathematical and metaphysical) truths rests on the principium contradictionis.

If we turn from the general principles to their application in detail, we find a separate proof for the inevitableness or salutary nature of each of the three kinds of evilthe metaphysical evil of created existence, the physical evil of suffering (and punishment), and the moral evil of sin.

Metaphysical evil is absolutely unavoidable, if a world is to exist at all; created beings without imperfection, finiteness, limitation, are entirely inconceivablesomething besides gods must exist.

Then, moral evil is connected with metaphysical evil: created beings cannot be absolutely perfect, hence, also, not morally perfect or sinless.

On Evidence in the Metaphysical Sciences, a prize essay crowned by the Academy, 1764; Phaedo, or on Immortality, 1767; Jerusalem, 1783; Morning Hours, or on the Existence of God, 1785; To the Friends of Lessing (against Jacobi), 1786; Works, 1843-44.

If only there were metaphysical axioms!

When once the clearness and distinctness of conceptions had been taken in so purely formal a sense, it was inevitable that in the end, as productivity became less, the principle should be weakened down to a mere demand for the explanation and elucidation of the metaphysical ideas present in popular consciousness.

As Descartes began with the metaphysical dualism of extension and thought, so Kant begins with the noëtical dualism of intuition and thought.

He shares in the former's interest in psychology, in the latter's foundation of metaphysical knowledge on inner experience, and in the dislike felt by both for Hegel; while, on the other hand, he differs from Herbart in his empirical method, and from Schopenhauer in the priority ascribed to representation over effort.

The third and fourth books of The World as Will and Idea, which develop the aesthetic and ethical standpoint of their author, stand in as sharp a contradiction to the first (poëtical) and the second (metaphysical) books as these to each other.

Morality presupposes pessimistic insight into the badness of the world and the fruitlessness of all desire, and pantheistic discernment of the untruth of individual existence and the identity in essence of all individuals from a metaphysical standpoint.

For the rest, Genovesi thus advises his friends: Study the world, devote yourselves to languages and to mathematics, think more about men than about the things above us, and leave metaphysical vagaries to the monks!

The positive stage of a science, which begins when we learn to explain phenomena by their laws, is preceded by two others: a theological stage, which ascribes phenomena to supposed personal powers, and a metaphysical stage, which ascribes them to abstract natural forces.

In the second, the metaphysical, period, the acts of divine volition are replaced by entities, by abstract concepts, which are regarded as realities, as the true reality back of phenomena.

It is not only the human mind in general that exhibits this advance from the theological, through the metaphysical, to the positive mode of thought, but each separate science goes through the same three periodsonly that the various disciplines have developed with unequal rapidity.

While some have already culminated in the positive method of treatment, others yet remain caught in the theological period of beginnings, and others still are in the metaphysical transition stage.

Mathematics entered on its positive stage at quite an early period, chemistry and biology only in recent times, while, in the highest and most complicated science, the metaphysical (negative, liberal, democratic, revolutionary) mode of thought is still battling with the feudalism of the theological mode.

The political preponderance of the legists corresponds to the intermediate, metaphysical stage.

I have been sometimes half inclined to put my manuscripts in the fire, and to exclaim with Dryden, respecting some metaphysical subject "I cannot bolt this matter to the bran.