Verb forms

[belly_ttt]

I came across some sentences, such as:
But to love her, I just need her everywhere
To please him is easy
Love a person is so hard
Running makes me exhausted
Living is easy with eyes closed

Why "to live is to fight" but not "living is to fight"
So, when to use to infi/ gerund or bare?

[petreem]

hi .well there is no rule for this ..there a list with the verbs which can be used as gerunds only.others that can be used as infi's only and those that can be used in both forms..now " live" and the other verbs in the sentences u mentioned above can be used as an infinitive. but theres a rule thats says what parts of speech are compatible with gerunds and the others compatible with infiniitves..both gerunds and infi's can be used as nouns in the subject..so maybe youd like to fetch those rules and the list..by the way do you know what does ' disagreeably satisfied" mean ?