Astikaya means a substance that exists and has many parts or divisions (pradeshas). In Jainism, five substances are called Astikaya because they exist and are made up of many pradeshas:

• Jiva (soul)
• Pudgala (matter)
• Dharma (medium of motion)
• Adharma (medium of rest)
• Akasha (space)

Kala (time) is not considered Astikaya because it does not have multiple parts in the same way.

So, Astikaya = that which exists and is composed of many parts. The idea is that these five substances pervade the universe in numerous divisions, while Kala is treated differently in some texts.

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