The Compendium of Caraka 2.4.4_1

2.4.4_1

yadā hyete trayo nidānādiviśeṣāḥ parasparaṃ &nānubadhnantyathavā kālaprakarṣādabalīyāṃso 'athavā 'anubadhnanti na tadā vikārābhinirvṛttiḥ, cirādvā 'apyabhinirvartante, tanavo vā bhavantyayathoktasarvaliṅgā vā; viparyaye viparītāḥ; iti sarvavikāravighātabhāvābhāvaprativiśeṣābhinirvṛttiheturbhavatyuktaḥ//

For when these three particular factors—etiology and so forth—do not combine with one another, or are weaker due to the lapse of time, or do not combine [completely], then manifestation of disease does not occur; or they manifest after a long time, or are slight, or lack all the stated symptoms; in the opposite case, it is the reverse. Thus the cause of the particular variation in the existence or non-existence of prevention of all diseases has been stated.