Page:Russell - An outline of philosophy.pdf/138

126 that there is. Therefore it can be no part of legitimate science to assert or deny the persistent entity; if it does either, it goes beyond the warrant of experience.

The following is a verbally cited passage in the letter referred to objecting to what was said above about "force":

"The concept of Force is not of physical but of psychological origin. Rightly or wrongly it arises in the most impersonal contemplation of the Stellar Universe, where we observe an infinite number of spherical bodies revolving on their own axes and gyrating in orbits round each other. Rightly or wrongly, we naturally conceive of these as having been so constituted and so maintained by some Force or Forces."

We do not, in fact, "observe" what it is here said that we observe; all this is inferred. What we observe, in astronomy, is a two-dimensional pattern of points of light, with a few bright surfaces of measurable size when seen through the telescope (the planets), and of course the larger bright surfaces that we call the sun and moon. Most of this pattern (the fixed stars) rotates round the earth once in every twenty-three hours and fifty-six minutes. The sun rotates in varying periods, which average twenty-four hours and never depart very far from the average. The moon and planets have apparent motions which are more irregular. These are the observed facts. There is no logical impossibility about the mediæval doctrine of spheres rotating round the earth, one for each planet and one for the stars. The modern doctrines are simpler, but not one whit more in accordance with observed facts; it is our passion for simple laws that has made us adopt them.

The last sentence of the above quotation raises some further points of interest. "Rightly or wrongly", the writer says, "we naturally conceive of these as having been so constituted and so maintained by some Force or Forces." I do not deny this. It is "natural", and it is "right or wrong"—more specifically, it is wrong. "Force" is part of our love of explanations. Everyone knows about the Hindu who thought that the world does not fall because it