First is a high thought around which life can be woven. Highest is God within me and in all, all within God and, God is the All.
Strong and pure synthesis when all the different elements of our nature keep this thought as a beacon and guide before them and function accordingly.
It could be Love or Truth or anything that is high and universal.
Pure means here to act under the influence of the Highest Ideal, in tune with it.
Affectioneatly,
Alok Da