Is knowledge of the risk necessary for the applicability of volenti non fit injuria?

The maxim, be it observed, is not ‘scienti non fit injuria’ but ‘volenti’. Knowledge is not a conclusive defence in itself. But when it is knowledge under circumstances that leave no open but one, namely, that the risk has been voluntarily encountered, the defence is complete. It is necessary to prove that the person injured knew of the, and voluntarily took it. Mere knowledge of the risk or danger is not sufficient, knowledge of the risk is necessary but it alone cannot attract the application of the maxim volenti non fit injuria. For application of the maxim the plaintiff must not only have the knowledge, but also the consent to run the risk.