When an individual daringly meets life he cannot expect all the time , happy situations, favourable circumstances and a conducive arrangement of chances in his field of activity. Ordinarily , a weak man suddenly feels dejected and is tempted to leave his field of work when it is only half done. Many lose their chances of achieving the highest and desert the field of action almost at the moment when, perhaps, victory is round the corner. In order to ‘stick to his guns’ man needs a secret energy to nurture and nourish his exhausted and fatigued morale, and this sacred energy welling up in his well integrated personality is ‘fortitude’.
Strength of Faith, Conviction in the Goal, Consistency of Purpose, Vivid Perception of the Ideal and a Bold Spirit of Sacrifice cultivated diligently – all these form the source from which fortitude gushes down to remove exhaustion, fatigue and despair. (16.3)
Holy Gita Ready Reference by Swami Chinmaya