Yogakaraka and Raja Yoga - the beauty of Saturn and Venus
Let's talk about what a "yogakaraka" planet is. We'll start by understanding the word itself. "Yogakaraka" has two component words: Yoga and Karaka. The later, "karaka" means "the doer" like the one who is the "agent" or "catalyst" or "actor." The former, "yoga" means "union." Laypeople think about astrology in terms of isolated factors: a sun sign, or a moon sign, or maybe a rising sign - but seldom do they think about how these singular factors combine together to form unions. However a real astrologer thinks ONLY in terms of combinations - and in combinations of combinations. Special combinations ("yogas") have been taken note of over the centuries and have been given unique names, like "buddha-aditya yoga" or "gaja keshari yoga" etc. etc. etc.
However, in astrology when you simply say "yoga" without a special clarification before hand (as is that case in the term "yoga-karaka"), you are understood to be referring to the most important yoga: the "raja-yoga" (king of combinations). So let's take a minute to understand what a raja-yoga is.
Actually there are two categories, at least, of Raja-Yogas. "Raja" means king, if the term raja-yoga means "king of yogas" then we are talking about one category of the combination, which is clearly and simply defined. But there is another category of yogas which also aquired the title "raja-yoga" because they two are very powerful and can elevate the horoscope in which they appear to a "kingly status." Let's set aside the second category of Raja-Yogas, for it is not pertinent to understanding what a "Yogakaraka" planet is.
The main category of Raja-Yoga is more properly known as a dharma-karma-adhipati yoga. This means "combination between the lords of purpose and the lords of action." The central, angular houses (1, 4, 7, and 10... the "kendras") are houses of manifest action (action). The triangular houses (1,5, and 9 ..."the konas") are houses of motivation and purpose carrying over from previous lifetimes. When a planet owning a house of motivation combines in a favorable mutual relationship with a planet owning a house of action... the individual experiences a harmony between what they WANT to do and what they actually end up doing. There is a harmony in their purpose and their action. Such harmony elevates them to great success, often of a kingly status.
Take, for example, an Aries ascendant (in a sidereal zodiac with a whole-sign house system, as is the norm for Vedic astrology). For Aries ascendant, the 9th House (a triangular house, a house of purpose) is Sagittarius, which is owned by Jupiter. The 10th House (an central house, a house of action) is Capricorn, owned by Saturn. Is, if in an Aries ascendant chart, Jupiter and Saturn have some sort of mutual relationship (they are conjunct or in mutual full aspect, or they exchange houses) then a Raja-Yoga forms and the person experiences a harmony and synchronicity between their purpose and action. The exact nature of this harmony will manifest according to the houses it involves by placement, and the aspects it recieves, etc.
That's one example of a Raja-Yoga of the primary type. Now we know enough that we can directly explain what a "yogakara" planet is. Take Taurus for example. The 9th House for a Taurus ascendant is Capricorn, and the 10th is Aquarius. Both of these houses (both a house of purpose and a house of action) are owned by a SINGLE planet: Saturn. Therefore Saturn is IN AND OF ITSELF a raja-yoga for the Taurus ascendant.
This is the meaning of the term "yoga-karaka" - for Taurus ascendants, Saturn is a planet who in an of himself creates ("Karaka") a raja-yoga ("Yoga").
Venus owns Taurus. Venus also owns Libra. In the never ending beauty of ancient astrological symmetry we find that for Libra ascendant the 4th house (a central, action house) and the 5th house (a triangular, purpose house) are Capricorn and Aquarius respectively. Again both owned by Saturn. Therefore for either sign owned by Venus, Saturn is a yogakaraka: a "kingly combination in a single planet."
Even more beautifully symmetrical. Suppose Saturn's Capricorn is the ascendant. In that case the 5th house (triangular, purpose house) is Taurus and the 10th house is Libra (central, action house). Both Taurus and Libra belong to Venus. Thus for Capricorn ascendants Venus
is the Yogakaraka.
And to polish it off, take Saturn's other sign, Aquarius, as the ascendant. In this case, the 4th house (central, action) is Taurus and the 9th house (triangular, purpose) is Libra - both Venus' signs! So again Venus is the Yogakaraka.
So the beautiful rule here is that for any ascendant ruled by Venus, Saturn is extremely beneficial and important, as the yogakaraka planet. And conversely for any sign ruled by Saturn, Venus is extremely beneficial and important, returning the favor as the yogakaraka planet.
What does this teach us about human nature? It shows that Sensuality is most beneficial when it is exersized with restraint, caution and patience. And it shows that wisdom and prudence is not at its best unless it is aided by appreciation for beauty, art, and love.