Planets, signs...have multiple potentials for form of expression.
Venus, for example, is said to rule "beauty". But beauty has two faces, as do coins, and the other face is ugliness.
The reason that we must take care in judging the condition of any planet is to gauge the nature of its expression. There is a sort of sliding scale of expression for any planet, going from the extreme pole of "good" to the other pole of "bad." Usually the expression of a planet's energies falls somewhere between the two extremes.
It is by analyzing and interpreting each of the conditions that affect a planet that we can judge its probable forms of expression. The condition of the lord of the planet (Venus in Aries is ruled by Mars) disposes the planet to behave in a certain way. The sign itself is important, of course, but too often we ignore the lord of the sign.
The interpretation of a planet, and of the horoscope as a whole, is conditional. One thing is conditioned by another, and the conditioning reverberates throughout the chart.
The student of astrology should understand that there is nothing mysterious in the art. [Astrology is deeply mysterious, but I want to emphasize the common-sense and practical view, because students tend to want to see the mysterious and lose sight of the down-to-earth nature of interpretation.]
Take Venus in the First House. Venus rules "refinement"; but then too it rules "coarseness". The task of the astrologer is to determine where, on the scale of values ranging from refined to coarse a particular Venus will register.
Suppose we have Venus in Aries, rising. But Venus is squared by Saturn in Capricorn. Well, what is the nature of Saturn, and what is the nature of Capricorn -- an Earth sign? Might we think that Saturn in Capricorn, probably in the Tenth in the example, is "careful of appearances"? Earth signs are by and large conventional. But Aries is a Fire sign and very self-expressive and individualistic, leaning toward the new and daring. The astrologer then faces the problem of which will dominate, the careful and conservative Saturn or the daring, self-expressive Venus? But of course, the native of the horoscope lives with the same conflict faced by the astrologer. By looking at Mars (lord of Aries) and the other aspects to Venus, and well as her situation with regard to Sun, her motion, the Sixth House (which rules clothing and physical self-care), as well as the Moon (image).... we might discover how this person dresses, what appearance she will project.
But all this is too complex, too complicated, you say? Well, yes it is. But then human beings tend to be complex and complicated, too.
So, how do we interpret a horoscope?
Let's set aside the horoscope. Let's turn to a painting by Van Gogh called "Prisoner's Walk." It's attached here.
Van Gogh painted himself into the "portrait". See him there, right up front? He's the only prisoner looking your way.
Look at the colors.
Notice that the walls are so high they go right up out of the picture.
The prisoners are walking round and round and round, in a never-ending circle.
And so on.... We take the details, but we also take the whole. One without the other is incomplete.
Interpret the picture. Everything created by a person is nothing more than a projection of the inner self onto the canvas of life. What was Van Gogh's inner world like?
The same principles apply to the interpretation of horoscopes.