Thus while Induction has the noble office of yielding knowledge of the universe, and guiding action, Metaphysics has the yet nobler office of ministering to the formation of character.

Relation of

Mathe

matics to the Induc

NOTE A.

Ir might perhaps appear a deficiency in this work if, while I state my views on the relation of the Inductive and the Metaphysical sciences to each other, I were to say nothing on their relation to Logic and Mathematics.

Logic and Mathematics are formal sciences; that is to say, their subject-matter consists in abstractions. Metaphysics and the inductive, or physical, sciences, on the contrary, are real sciences; that is to say, their subject-matter consists in things Metaphy- which have existence in the universe of matter and mind.1 We sical may then classify the sciences thus:

tive and

sciences.

Another classification, however, is perhaps better.

The first and most fundamental division of the sciences is that into abstract logic on the one side, and the applications of logic on the other. Every possible science comes under one of these two heads ;-every science other than logic consists in the Position of application of logic to some particular class of subjects. And Logic. logic, while it cannot be classed either as an inductive or as a metaphysical science, belongs to both the inductive and the metaphysical series; for its data are at once external to the mind like those of physical science, and internal to the mind like those of metaphysics; in other words, they are at once laws of the external universe and laws of thought.

Position of But mathematics? The axioms of mathematics are no doubt Mathemalike those of logic, not only laws of the external universe, but

tics.

1 It is said in popular language, that the subjects of metaphysics are in a high degree abstract; but this only means that they require a high degree of mental abstraction to grasp them.

2 See "Habit and Intelligence," vol. ii. p. 202.

also laws of thought; but mathematics is associated not with metaphysics, but with the inductive sciences, because its subjectmatters, that is to say the properties of time and space, are thought of as external to the mind.

On this basis we may classify the sciences as follows:

Ethics and

Ethics, or the theory of the moral sense, belongs to Psycho- Position of logy, and, as such, is partly inductive and partly metaphysical. PsychoIt may be thought a proof of inaccuracy in this classification, logy. that Psychology is placed in this double position. It is not so, however. Psychology is, as a matter of fact, capable of being studied either from the Inductive or from the Metaphysical point of view; and there is no more error or confusion in recognizing this, than in recognizing the fact that the theory of spectrum analysis belongs at once to Optics and to Chemistry.2

NOTE B.

Ir may be thought a contradiction to say in one place that Apparent contradic"force is only explicable as a function of conscious mind and tion exwill" (p. 14); and elsewhere that the facts and laws of force, plained. which constitute the data of dynamical science, are external to the mind (p. 25). There is, however, no real contradiction: it is only a case of looking at the same subject from two opposite points of view successively. Force is a fact of consciousness whenever we are conscious of our own mental activity; but the law of the equality of action and re-action, the law of the conservation of energy, and all the other physical laws of force, are external to the mind in the sense that they are known by observation only, and could not conceivably be made known by any interrogation of consciousness.

For the classification of the inductive sciences, see "Habit and Intelligence," Chapter 43.

2 See the same chapter, p. 199.

CHAPTER II.

THE METAPHYSICAL INTERPRETATION OF NATURE.

Problem of the under

THOUGH the proper purpose of the preceding chapter

is only to define the province of Metaphysics, and to state its most important problems, it has been impossible to avoid in some degree anticipating the subjects of future chapters, and stating, or at least indicating, my own conclusions as to the true solution of those problems. The first of these problems is that of the underlying lying reality, or what, using a mathematical expression, I have reality of called the interpretation, of the physical world; and I have the physical world, declared my agreement with the doctrine of Berkeley and Mill, that the material universe is known to us only as consisting of "permanent possibilities of sensation;” or, in other words, that all our conceptions and all our knowledge of material things are ultimately resolvable into the knowledge that they have the properties of being able to excite certain sensations in us.

But it is impossible to rest in this conclusion as exhausting the subject. It may be all that we can know; but if so, there must be something that we cannot know. We may have run out all our sounding-line, but let us not therefore think that we have touched the bottom of the

ocean.

To put the question in a form which will address not only the understanding but also the imagination :-We who see and feel the world of matter around us are the latest and highest product of that world. But we know that the world of matter existed before it had given origin to sentient beings like us to see and feel it. During those

tions of it.

vast periods of cosmic time, which perhaps were in magnitude to the geological periods what the geological are to the historical, while the original nebula was condensing into worlds and before those worlds were sufficiently consolidated or sufficiently cooled down to support life on their surfaces; how can it be said that the universe of matter consisted in "permanent possibilities of sensation," when as yet there were no beings in which any sensations could be excited? To us, things have no reality except as they are perceived, or capable of being perceived. As Berkeley has tersely put it, "their Esse is Percipi." But what was the underlying reality of things when as yet there were none to perceive them? This is identical with apart from the question, what is the underlying reality, or the in- our percepterpretation, of things in themselves, apart from being perceived? Mill's reply is, that substance, or what I have Mill's called underlying reality, has no meaning at all; and that reply: not only matter is known to us as a permanent possibility of sensation, but that it is nothing else, and has no other meaning. This doctrine is perhaps impossible to refute in why unsatisfactory. any direct way, but it involves the consequence that during the period when there were no sentient beings in the universe of matter, that universe had no true existence except in relation to those sentient beings which were to come into existence afterwards; and that if the universe of matter had never become the home of any sentient beings, it would not have had any existence at all. Berkeley's reply to the same question is, that even when Berkeley's material things are not perceived by us or by beings like reply: us, they are still at all times the objects of the Divine perception. This is at least not absurd, but it appears to assume that the Divine perceptions are of the same nature as ours; and this is not only unproved and incapable of why unsabeing proved, but appears very unlikely; for our powers of perception are developed out of our powers of sensation, but none of the Divine powers are so developed, or developed at all.

tisfactory.

To the question, What is the underlying reality of No full things considered in themselves? there is then no answer

reply is

possible.

Another line of inquiry.

Statical and dynamical properties of

matter.

except this, that we do not and cannot know. So that we end where we began. But we do not end as we began; for we have learned this, that there is. that which we do not and cannot know.

There is, however, another line of inquiry on this subject which does not lead to so purely negative a result.

When we consider the nature of matter as made known to us, not by the results of the most refined physical science but simply by our unaided senses, we recognize two distinct sets of properties in matter, which may, from our present point of view, be defined with sufficient accuracy as the statical and the dynamical; meaning by the statical properties, those of position, extension, form, and impenetrability; and by the dynamical, such properties as those of inertia, or the capacity of being acted on by force; and weight, or gravity, which is itself a force. The stati- The statical properties are the most conspicuous ones, and it appears to have been chiefly on them that attention was concentrated during the metaphysical controversies of the The dyna- eighteenth century. But the physical science of the mical are present century has brought the dynamical properties of matter into greater prominence than the statical; and important. this change appears destined to work, perhaps almost unconsciously, a profound change in metaphysical conceptions as regards the external world, the mind, and their relation to each other,

cal were

formerly

most at

tended to.

now seen

to be as

The stati

The statical properties of matter present no analogies cal have no whatever with any of the properties of mind; and so long analogies with mind: as the attention of philosophers was chiefly directed to them, it was inevitable that, to those who agreed with the common sense of mankind in admitting the reality of a material world at all, the nature of its relation to the mind. appeared to be a perfectly insoluble mystery.

but the have:

But the dynamical properties of matter do present dynamical analogies, or rather one all-comprehending analogy, with the properties and functions of mind. Force, or causation, is a fact of the worlds of matter and of mind alike. In becoming conscious of its own activity, as distinguished from merely passive feeling, as for instance in directing

Force is a fact of both

matter and mind.