text: A cause is defined as an unconditional and invariable antecedent of an effect and an effect as an unconditional and invariable consequent of a cause. The same cause produces the same effect; and the same effect is produced by the same cause. The cause is not present in any hidden form whatsoever in its effect.
  The following conditions should be met:
  # The cause must be antecedent [Purvavrtti]
  # Invariability [Niyatapurvavrtti]
  # Unconditionality [Ananyathasiddha]
  Nyaya recognizes five kinds of accidental antecedents [Anyathasiddha]
  # Mere accidental antecedent. E.g., The colour of the potter's cloth.
  # Remote cause is not a cause because it is not unconditional. E.g., The father of the potter.
  # The co-effects of a cause are not causally related.
  # Eternal substances, or eternal conditions are not unconditional antecedents, e.g. space.
  # Unnecessary things, e.g. the donkey of the potter.
  Nyaya recognizes three kinds of cause:
  # Samavayi,  material cause, e.g. thread of a cloth.
  # Asamavayi, colour of the thread which gives the colour of the cloth.
  # Nimitta, efficient cause, e.g. the weaver of the cloth.