Until the 18th century, astrology was often based on the assumption that there was a physical connection between the positions and movements of planets as well as stars and earthly events, often referred to as "natural astrology", which was supposed to have an effect on the weather, agriculture and in medicine, for example. On the other side, far less clearly understood in physical terms, was especially birth chart astrology with its effects on people's lives, which often claimed to be able to predict future developments in human life, and which often enough repeated in its interpretations actual or supposedly long handed down astrological experiences going back a long way. In birth horoscope astrology this goes back, among other things, to the idea of macrocosm (universe) and microcosm (earth or man), which are thought to relate to each other as a unity. Man as a microcosm is a mirror of the macrocosm, there is a correspondence of the human body with parts of the cosmos, and thus a system of mutual dependencies of the parts of the cosmic organism. Some assume a direct influence of the macrocosm on the microcosm (effect theory), others believe merely in a reflection (symbol theory). "As above, so below," as the Hermetic Tabula Smaragdina puts it. This worldview is religious in a broader sense.
In contemporary Western astrology, four views of the nature of astrological statements can be distinguished. Esoteric astrology refers to knowledge communicated by divine beings or "initiates". Symbolic astrology presupposes a traditional system of interpretation in which astronomical facts are ascribed a meaning in relation to earthly ones. In addition, an "astrology as a science of experience" is advocated, which strives for an empirical foundation, and finally there is the influence hypothesis, according to which the astrological planets affect living beings in a way that is not yet known in detail.