prefers regarding it as a tree. He loves the image of the
umbrageous Igdrasil better than that of the Strasburg clock. A
machine may be defined as an organism with life and direction outside;
a tree may be defined as an organism with life and direction within.
In the light of these definitions, I close with the conception of
Carlyle. The order and energy of the universe I hold to be inherent,
and not imposed from without, the expression of fixed law and not of
arbitrary will, exercised by what Carlyle would call an Almighty
Clockmaker. But the two conceptions are not so much opposed to each
other after all. In one fundamental particular they at all events
agree. They equally imply the interdependence and harmonious
interaction of parts, and the subordination of the individual powers
of the universal organism to the working of the whole.

Never were the harmony and interdependence just referred to so clearly
recognised as now. Our insight regarding them is not that vague and
general insight to which our fathers had attained, and which, in early
times, was more frequently affirmed by the synthetic poet than by the
scientific man. The interdependence of our day has become
quantitative--expressible by numbers--leading, it must be added,
directly into that inexorable reign of law which so many gentle people
regard with dread. In the domain now under review men of science had
first to work their way from darkness into twilight, and from twilight
into day. There is no solution of continuity in science. It is not
given to any man, however endowed, to rise spontaneously into
intellectual splendour without the parentage of antecedent thought.
Great discoveries grow. Here, as in other cases, we have first the
seed, then the ear, then the full corn in the ear, the last member of
the series implying the first. Thus, as regards the discovery of
gravitation with which the name of Newton is identified, notions more
or less clear concerning it had entered many minds before Newton's
transcendent mathematical genius raised it to the level of a
demonstration. The whole of his deductions, moreover, rested upon the
inductions of Kepler. Newton shot beyond his predecessors; but his
thoughts were rooted in their thoughts, and a just distribution of
merit would assign to them a fair portion of the honour of discovery.

Scientific theories sometimes float like rumours in the air before
they receive complete expression. The doom