The first traceable beginnings of it are to be found in the phenomenon of crystallisation; we have there, we are told by the highest scientific authority, '_the first gropings of the so-called vital force_;' and we learn from the same quarter, that between these and the brain of Christ there is a difference in degree only, not in kind: they are each of them '_an assemblage of molecules, acting and re-acting according to law_.' '_We believe_,' says Dr.Tyndall, '_that every thought and every feeling has its definite mechanical correlative--that it is accompanied by a certain breaking up and re-marshalling of the atoms of the brain_.' And though he of course admits that to trace out the processes in detail is infinitely beyond our powers, yet '_the quality of the problem and of our powers_,' he says, '_are, we believe, so related, that a mere expansion of the latter would enable them to cope with the former_.' Nowhere is there any break in Nature; and '_supposing_,' in Dr.Tyndall's words, '_a planet carved from the sun, set spinning on an axis, and sent revolving round the sun at a distance equal to that of our earth_,' science points to the conclusion that as the mass cooled, it would flower out in places into just such another race as ours--creatures of as large discourse, and, like ourselves, looking before and after.

The result is obvious.

Every existing thing that we can ever know, or hope to know, in the whole inward as well as in the whole outward world--everything from a star to a thought, or from a flower to an affection, is connected with certain material figures, and with certain mechanical forces.

All have a certain bulk and a certain place in space, and could conceivably be made the subjects of some physical experiment.

Faith, sanctity, doubt, sorrow, and love, could conceivably be all gauged and detected by some scientific instrument--by a camera or by a spectroscope; and their conditions and their intensity be represented by some sort of diagram.
These marvellous achievements, as I have said, have been often before dreamed of.