In "On Old Age and Death" Seneca writes that "old age is a time of bloom" and a great time for one's mind. Seneca also counsels to be ready for death and that it could come at any time. He also writes that one must learn how to die and that "he who has learned to die has unlearned slavery." His belief is that at death "there is only one chain which binds us to life, and that is the love of life." I think fatalism comes in to play with this letter because death is a part of life and also the idea that do not worry about what is beyond your control is a big lesson in this teaching.
"On the Trials of Travel" was written by Seneca after a long voyage from Baiae to Naples. He finds it foolish that we will fear one thing more than another even when they will both end the same way. Seneca also ponders about the soul and remarks that the soul can not be "arrested or destroyed inside of the body" but can escape through any part of the body. This writing uses the logic of do not concern yourself with things that are beyond your control for if you fear your soul dying you should not because since it cannot be crushed then it can not be harmed.