The idea that all matter is composed of elementary particles dates to as far as the 6th century BC. The Jains in ancient India were the earliest to advocate the particular nature of material objects between 9th and 5th century BCE. According to Jain leaders like Parshvanatha and Mahavira, the ajiva (non living part of universe) consists of matter or pudgala, of definite or indefinite shape which is made up tiny uncountable and invisible particles called permanu. Permanu occupies space-point and each permanu has definite colour, smell, taste and texture. Infinite varieties of permanu unite and form pudgala. The philosophical doctrine of atomism and the nature of elementary particles were also studied by ancient Greek philosophers such as Leucippus, Democritus, and Epicurus ; ancient Indian philosophers such as Kanada, Dignāga, and Dharmakirti ; Muslim scientists such as Ibn al-Haytham, Ibn Sina, and Mohammad al-Ghazali ; and in early modern Europe by physicists such as Pierre Gassendi, Robert Boyle, and Isaac Newton. The particle theory of light was also proposed by Ibn al-Haytham, Ibn Sina, Gassendi, and Newton.