But in the estimation of the divine philosophers this proof and assurance is not reliable; nay, rather, they deem the standard of the senses to be false because it is imperfect. Sight, for instance, is one of the most important of the senses, yet it is subject to many aberrations and inaccuracies. The eye sees the mirage as a body of water; it regards images in the mirror as realities when they are but reflections. A man sailing upon the river imagines that objects upon the shore are moving, whereas he is in motion, and they are stationary. To the eye the earth appears fixed, while the sun and stars revolve about it. As a matter of fact, the heavenly orbs are stationary, and the earth is turning upon its axis. The colossal suns, planets and constellations which shine in the heavens appear small, nay, infinitesimal to human vision, whereas in reality they are vastly greater than the earth in dimension and volume. A whirling spark appears to the sight as a circle of fire. There are numberless instances of this kind which show the error and inaccuracy of the senses. Therefore, the divine philosophers have considered this standard of judgment to be defective and unreliable.