Page:The Solar System - Six Lectures - Lowell.djvu/89



conditions, owing to its size, ran more rapidly through its successive stages, again owing to its size, and will come to an end sooner for the same reason.

As a detail of this, life on Mars must take on a very different guise from what it wears on Earth. It is certain that there can be no men there; that is as certain as anything well can be. But this does not preclude a local intelligence equal to, and perhaps easily superior to, our own. We seem to have evidence that something of the sort does exist there at the present moment, and has made imprint there of its existence far exceeding anything we have yet left upon mother Earth.

In conclusion, let me warn you to beware of two opposite errors; of letting your imagination soar unballasted by fact, and, on the other hand, of shackling it so stolidly that it loses all incentive to rise. You may come to grief through the first process; you will never get anywhere by the second. Take general mechanical principles for compass and then follow your observations. Imagination is as vital to any advance in science as learning and precision are essential for starting points.