The Sun in the horoscope is the Logos image, the eternal principle living in the individual as a vital impulse.
At first glance, the mythological attribution of the star to the deity appears quite elaborate. There are two representative figures of the solar role in the Greek pantheon: Helios and Apollo.
Helios (Gr. Ἥλιος), related to the Latin Sol and the Sanskrit Sūrya, is considered a minor deity in classical Greece, not part of the twelve Olympian deities. In late antiquity, his role – thanks to his identification with the solar divinities of the Roman era – acquires greater visibility. Son of the Titans Hyperion (god of light and alertness) and his sister Teia (goddess of vision), Helios becomes the representation of the physical sun. Among his designations and nicknames (sometimes depicted as minor deities), we mention Elektor (the radiant one), Terpsimbrotos (who cheers mortals) and Hekatebolos (with sharp arrows, regarding the sun’s rays).
Helios is typically depicted as a handsome youth with a crown or halo of sunlight who crosses the sky daily in his chariot drawn by four steeds. Besides being seen as a personification of the solar disk, Helios represents the creative power inherent in physical manifestation, the source of life and renewal.
But let us come to the conflict of attributions. Apollo, god of Olympus – son of Zeus and Leto – is mainly recognised as the god of archery, music, dance, prophecy, healing and disease, protector of shepherds and flocks, and dedicated to the care of youth: a god with different responsibilities. In Homeric literature, Apollo is also the bearer of plagues sent to humanity with arrows shot from his bow. In the late Hellenistic period, in the cultic and philosophical texts, his identification – as the god of light – with the Sun began to take hold through the cult of Phoebus – from the Greek Φοῖβος, brilliant – one of the epithets of Apollo. Even the poets of Latin classicism begin to use Phoebus as the nickname for the god Sol. But it must be said that, in most mythological narratives, Apollo and Helios appear distinct.
In late antiquity, in that period of transition between classical antiquity and the European Middle Ages, Helios took on the features and elements of other deities. In 274 AD, on 25 December, the emperor Aurelian instituted the cult of Sol Invictus (Unconquered Sun), which brings together aspects of other deities such as Mithras and Harpocrates, the Hellenic representation of the god Horus. With Julian, the last pagan emperor, we witness the apotheosis of the figure of Helios, who becomes the primary divinity. Julian, emperor philosopher and author of texts in Greek, combines elements of Mithraism with Neoplatonic doctrines, and Helios seems to be the expression of a trinity: the One, which governs the realm of Platonic forms; Helios-Mitra, the god of the intellectual realm; and the Sun, the physical plane manifestation of Helios. As a centralising expression of this trinity, Helios is the Logos, the divine word.
In this tripartition, we note the association between the figures of Apollo and Helios. The pure potential of manifestation reveals itself as energy and matter, from whose subsequent hierogamy – or attraction – the plane of forms arises. With the introduction of the fourth term, which is like an immanent replica of the transcendent One, the double attribution of the Sun is clarified, of which Helios represents the physical vehicle – the chariot of the Sun driven by him in his daily run – while Apollo preserves his spiritual traits. In a broader sense, it can be hypothesised that some of Apollo’s qualities are expressions of the vivifying solar energy, the harmonization of which in the individual is a source of health (Apollo the healer). At the same time, in the event of conflicts, the disease manifests itself (Apollo bearer of pestilence). The same goes for his beauty, youth patronage, etc. Everything in him reveals the centrality of the Sun, but as if hidden by appearances. It is the hidden Sun, the Sun behind the physical sun.
In the Latinisation of the cult, Helios appears associated with the bull-god Mithras. The Mithraic mysteries were followed significantly in the Roman Empire, starting with Christianity and up to the 4th century AD. Such rites have always made it challenging to understand Mithraism, formerly associated with pre-existing Iranian cults. The thesis accepted today is that the Mithraic mysteries have a character of relative originality. The Mithraic cult is a succession of states which lead the novice to overcome the taurine nature in the animal sense, up to their integration on the throne of the Eagle. It is the final elevation and liberation from the domination of nature enslaved to instincts; the “bellow” that sounds from the officiant’s throat is proof of the yoke of the bull. We find a sign of this struggle in the astrological symbolism of Taurus and Scorpio: when the poisonous tail of Scorpio pierces the nature of Taurus – the opposite sign – the bond with the earthly density is dissolved, and Scorpio becomes the Eagle. In that way, it resolves the dualistic contradiction between spirit and matter by announcing its release from the bonds.
As regards the Sun-Mithras association of which traces are found, it is considered by some to be a gloss inserted erroneously by some scribes; in fact, the initiate of Mithras is the one who “defeats” the Sun, who challenges it face to face until he integrates it into himself, becoming, in turn, the “centre”. But the contradiction is only apparent because if the aim is to assume the central and centralising role of the Sun, the meaning of the double attribution becomes clear: Mithras “resolves” the Sun by ensuring that the human microcosm, through the centre of itself regained, becomes an exact semblance of the macrocosm in which the central star, with its retinue of planets, is the visible image of the occurred reunion.
The solar symbolism
Attempting to distinguish between the Sun as the vital node of the individual and the planes of the horizon and the meridian, which form the cross of incarnation from the terrestrial point of view, is not easy. These are two different systems of reference, both comprising human individuality. The axes of the horoscope chart represent the architecture of the field of consciousness, i.e., the form through which consciousness expresses itself. The point of intersection of the axes is the Primum Mobile (first movable), an immaterial point, the potential for individual manifestation that unfolds through the axes. All this would be nothing without the solar presence, from whose light (where the eye is its somatic expression) emanates the energy of life and vision, the self. The ego represents its individualising stage in the earthly incarnation (one can again compare this relationship to the Puruṣa – Prakṛti dyad of the Saṃkhyā  or to the Spinoza’s Natura naturans – Natura naturata , making the necessary distinctions).
It is understood that the Sun is only the image of the Logos, the permanent principle of which the individual is a transitory manifestation. The Sun, therefore, represents the potency of Logos which reveals itself as the vital principle of the individual ego. It manifests itself in the architecture provided by the cross of incarnation. And the topocentric position of the Sun concerning the domification indicates the modalities of earthly representation of the solar principle, that is, in which way and in what guise the principle integrates into an individual life; we could call it primary destiny.
The presence of the Sun in the sign quantitatively characterises the solar energy gradient defined by the inclination of the Earth’s rotation axis on the orbital plane – the seasonal alternation. It causes a greater or lesser influx of energy and light at different times of the year. This fact is evident for the latitudes of the temperate belt, where we have the widest variety and regularity of climatic conditions. On the contrary, the equator and the poles represent the extremes, where the symbolic expression of the solar principle reaches its maximum strength and weakness. This will influence the individuals’ social manifestations, which will be limited by proximity to the poles and get greater expressiveness in tropical areas.
Referring to the individual nature, we will read the solar gradient as an imprint given by synchronising the unborn child with the surrounding seasonal environment. This analogical bond will then express itself as the true nature of human beings, the keynote of their life cycle. The whole meaning will, of course, be revealed by the combination of planetary and zodiacal configurations. However, the sun sign is the underlying motif, the plot that weaves the themes of one’s life.