[14] Cf. the author's Logik, bd. i, § 61.
[15] "Rationem vero harum gravitatis proprietatum ex phaenomenis nondum potui deducere, et hypotheses non fingo. Quicquid enim ex phaenomenis non deducitur, hypothesis vocanda est; et hypotheses seu metaphysicae, seu physicae, seu qualitatum occultarum, seu mechanicae, in philosophia experimentali locum non habent. In hac philosophia propositiones deducuntur ex phaenomenis, et redduntur generales per inductionem." Newton, at the end of his chief work.
[16] Logik, bk. iii, ch. v, § 2.
[17] Logic, bk. iii, ch. v, § 6, and end of § 2. Hume says in a note to section vi of his Enquiry Concerning Human Understanding: "We ought to divide arguments into demonstrations, proofs, and probabilities. By proofs Meaning such arguments from experience as leave no room for doubt or opposition." The note stands in evident contrast to the well-known remarks at the beginning of section iv, pt. i.
[18] Logic, bk. iii, ch. xxi, § 1.
[19] Alongside of these dynamic theories, there are to be found mechanical ones that arose just as early and from the same source, viz., the practical Weltanschauung. It is not part of our purpose to discuss them. Their first scientific expression is to be found in the doctrine of effluences and pores in Empedokles and in Atomism.
[20] Logic, bk. iii, ch. v, § 6.
[21] Vorträge und Reden, bd. ii, "Über den Ursprung und die Bedeutung der geometrischen Axiome."
[22] The only empiricism which can maintain that the same causes would, in conformity with the causal law, be given in the unobserved reality, is one which puts all events that can be regarded as causes in the immediately given content of perception as its members. Such a view is not to be found in Mill; and it stands so completely in the way of all further analysis required of us by every perception of events that no attention has been paid in the text to this extreme of extremes.
[23] Logic, 1874, buch i, kap. viii.