Particular angular distances between planets, or planets and other sensitive points, measured in degrees (°), minutes (') and sometimes seconds (") of arc. In ancient times, planets were held to "see" other planets at particular geometric positions determined by their rays, hence they took on an aspect of vision. In this way, signs were really in aspect rather than planets, and many traditional astrologers (especially those who follow the Indian or the Hellenistic systems of Whole Sign Houses) still hold that aspects must be in-sign and not out-of-sign. Modern astrologers generally do not take this view, but simply consider geometric relationships as aspects. Conjunction is also nowadays considered an aspect, even though the ancients did not call it such.