"As a visible symbol the vajra takes the shape of a sceptre (the emblem of supreme, sovereign power), and therefore it is correct to call it 'diamond sceptre.' This sceptre assumes a form corresponding to its function. Its centre is a sphere which represents the seed or germ of the universe in its undifferentiated form as 'bindu' (dot, zero, drop, smallest unit). Its potential force is indicated in pictorial representations by a spiral issuing from the centre of the sphere. From the undifferentiated unity of the centre grow the two opposite poles of unfoldment in form of lotus-blossoms, which represent the polarity of all conscious existence."