Arthur E. Waite - The Pictorial Key to the Tarot :
He has a form of the Crux ansata for his sceptre and a globe in his left hand. He is a crowned monarch - commanding, stately, seated on a throne, the arms of which axe fronted by rams' heads. He is executive and realization, the power of this world, here clothed with the highest of its natural attributes.
He is occasionally represented as seated on a cubic stone, which, however, confuses some of the issues. He is the virile power, to which the Empress responds, and in this sense is he who seeks to remove the Veil of Isis; yet she remains virgo intacta.
It should be understood that this card and that of the Empress do not precisely represent the condition of married life, though this state is implied.
On the surface, as I have indicated, they stand for mundane royalty, uplifted on the seats of the mighty; but above this there is the suggestion of another presence. They signify also - and the male figure especially - the higher kingship, occupying the intellectual throne. Hereof is the lordship of thought rather than of the animal world.
Both personalities, after their own manner, are "full of strange experience," but theirs is not consciously the wisdom which draws from a higher world. The Emperor has been described as:
(a) will in its embodied form, but this is only one of its applications, and (b) as an expression of virtualities contained in the Absolute Being - but this is fantasy.
P. D. Ouspensky – The Symbolism Of The Таrot :
After I learned the first three numbers I was given to understand the Great Law of Four--the alpha and omega of all.
I saw the Emperor on a lofty stone throne, ornamented by four rams' heads. On his forehead shone a golden helmet. His white beard fell over a purple mantle. In one hand he held a sphere, the symbol of his possession, and in the other, a sceptre in the form of an Egyptian cross--the sign of his power over birth.
"I am The Great Law," the Emperor said. "I am the name of God. The four letters of his name are in me and I am in all.
"I am in the four principles. I am in the four elements. I am in the four seasons. I am in the four cardinal points. I am in the four signs of the Tarot.
"I am the beginning; I am action; I am completion; I am the result.
"For him who knows how to see me there are no mysteries on earth.
"I am the great Pentacle.
"As the earth encloses in itself fire, water and air; as the fourth letter of the Name encloses in itself the first three and becomes itself the first, so my sceptre encloses the complete triangle and bears in itself the seed of a new triangle.
"I am the Logos in the full aspect and the beginning of a new Logos."
And while the Emperor spoke, his helmet shone brighter and brighter, and his golden armour gleamed beneath his mantle. I could not bear his glory and I lowered my eyes.
When I tried to lift them again a vivid light of radiant fire was before me, and I prostrated myself and made obeisance to the Fiery Word.