Astrology, as distinguished from Astronomy, is not simply a study of planets, stars and constellations but embraces within its scope the relationship between such heavenly bodies and mankind inhabiting the surface of the earth.

Indian seers of yore had synoptic views of knowledge and were not content with its departmentalization to such an extent as to be forgetful of its integrity and unity. So, in the last analysis Indian philosophy comprehended the so-called sciences, arts, sociology etc., and tried to establish that knowledge derived from all sources converged to the realization of the Ultimate.
Astronomy is the study of heavenly bodies as such: it seeks to classify them, determine their distances from earth, explain their origin and their mutual relationship. Astronomy is thus a pure science, where Astrology utilizes the knowledge of Astronomy to explain the physical, mental, moral and spiritual characteristics of individuals and of groups of individuals in a specific area of earth at particular points of time. This explanation may be precise when the particular point of time at which an individual’s or group's characteristics are to be determined is precisely known, because very minute variation from that will entail a wide departure from the characteristics so determined.
Modern science furnishes us with an instrument called spectroscope with the help of which we can analyze light from different sources, from the sun, planets and stars and know the elements which remain in them in the incandescent state and those in the gaseous form existing in their outer zone. The dark lines, called Fraunhofer lines, visible in the solar spectra indicate the elements present. When a man is born on earth at a particular time, he is subjected to the influences of the different kinds of light emanating from the heavenly bodies. The quality of such light incident on man at the time of his birth depends upon the respective positions of the planets vis-à-vis earth, vertical, oblique, horizontal, etc, the constellations in the midst of which they reside for the time and so on. It thus appears that the lights issuing from planets and stars influence the psychological and nervous system of the individual born, develop certain mental characteristics and thus determine the tenor of his life.

In this connection, it may be pointed out that the incidence of gamma ray on seeds interferes with their normal growth. After an explosion of an atom of hydrogen bomb the radio-active fall-outs which are in the shape of invisible rays affect human constitution and cause abnormalities in the progeny. Modern science tells that matter is ultimately reduced to waves and these waves which pervade every medium can penetrate human body and produce permanent effect on it and on the man as a whole. The spectroscopic examination of sunlight reveals that the spectrum has two parts, the visible and the invisible; the visible part consists of seven colours (light waves of different wave-lengths) and the invisible part consists of heat and chemical rays. It is believed that precise spectroscopic analysis of the lights of different planets and stars will disclose a wide gamut of influence on individuals derived from both the visible and invisible parts of their respective spectra. Though the planets have all been derived from the sun, their origin might not have been simultaneous and such origin having taken place at different points of time and from different parts of sun's body, the character of the light emanating from each and incident on earth might be divergent.

According to the theory of conditioned reflex enunciated by Pavlov, external stimuli have a great influence in determining the character of an individual. Russian biologists and social thinkers who are exponents of this doctrine have gone to the extreme of denying the existence of heredity and of somatic differences in living beings. The stimulus exerted by planets and stars on individuals has been overemphasized by certain astrologers to the extent that the destiny of a man is built by such planets and stars and he cannot reshape his life by any means. This theory of determinism was in consonance with the scientific thoughts that prevailed before the advent of Prof. Heisenberg who propounded from the study of electrons in an atom of an element that it is difficult to determine precisely the position of an electron at any particular time if its velocity is correctly known. Yet there has emerged the theory of probability which from the statistical study of the behaviors of electrons has sought to restore some amount of determinism.

It will thus appear that the astrologer’s version of human destiny cannot be pooh-poohed; it has got a stable basis on the modern scientific trends of thinking. Bold astrologers like Bhrigu have asserted that it is possible to prepare the horoscopes of all men and those who will be born on earth on the basis of the permutations and combinations of the positions of the sun, the moon, the different planets, popular constellations etc. It may be pointed out here that Rahu and Ketu which may be identified with the umbra and penumbra of the earth's shadow stand for the vicarious influence of earth as a planet on man's destiny. The part played by them cannot be scientifically explained, as Western astrologers have so long denied them any place in the Zodiac.

Indian seers have however emphasized the fact that in spite of the multitudes of differences that exist between man and man owing to geographical, psychological and economic differences caused by the influence of the planetary and astral worlds, there is inveterate urge in man, not located in any part of the human body, which leads him to transgress all differences, encourages in him a monistic view of life and achieves his self-realization in and through the Universe. It is the culture of Yoga that inhibits response to external stimuli, applies all the energies of the individual inwards, drives all biological impulses from the lower center to the brain and brings about culmination in the realization of the Infinite through the manifold and supreme development of the brain.