nd
"Force" are, so far as we can know, mere names for certain forms of
consciousness. "Necessary" means that of which we cannot conceive the
contrary. "Law" means a rule which we have always found to hold good,
and which we expect always will hold good. Thus it is an indisputable
truth that what we call the material world is only known to us under the
forms of the ideal world; and, as Descartes tells us, our knowledge of
the soul is more intimate and certain than our knowledge of the body.
If I say that impenetrability is a property of matter, all that I can
really mean is that the consciousness I call extension, and the
consciousness I call resistance, constantly accompany one another. Why
and how they are thus related is a mystery. And if I say that thought is
a property of matter, all that I can mean is that, actually or possibly,
the consciousness of extension and that of resistance accompany all
other sorts of consciousness. But, as in the former case, why they are
thus associated is an insoluble mystery.

From all this it follows that what I may term legitimate materialism,
that is, the extension of the conceptions and of the methods of physical
science to the highest as well as the lowest phenomena of vitality, is
neither more nor less than a sort of shorthand Idealism; and Descartes'
two paths meet at the summit of the mountain, though they set out on
opposite sides of it.

The reconciliation of physics and metaphysics lies in the acknowledgment
of faults upon both sides; in the confession by physics that all the
phaenomena of nature are, in their ultimate analysis, known to us only as
facts of consciousness; in the admission by metaphysics, that the facts
of consciousness are, practically, interpretable only by the methods and
the formulae of physics: and, finally, in the observance by both
metaphysical and physical thinkers of Descartes' maxim--assent to no
proposition the matter of which is not so clear and distinct that it
cannot be doubted.

When you did me the honour to ask me to deliver this address, I confess
I was perplexed what topic to select. For you are emphatically and
distinctly a _Christian_ body; while science and philosophy, within the
range of which lie all the topics on which I could venture to speak, are
neither Christian, nor Unchristian, but are Extrachristian, and have a
world of their own, which, to use language which will be very familiar
to your ears just now, is not only "unsecta