@Kalenda gives explanations and some examples of using the to-infinitive in the post: Can I start a sentence with To + verb?
To question one's existence would be natural
To start a sentence with an infinitive is bizarre
To talk to one's boss in the morning is every employee's desire
I wonder: Is the length of subjects before / complements etc after the 'be' critical here? Say,
To speak of ... [long subject] ... is ... long complement.
Is this good in English? I met examples when the first complement in To speak of ... is ... was very long.
To speak of rigorous separation and a willingness to abandon part of what was hitherto one’s own but has become dangerous is to use the classic language of anxiety. The complement ofTo speak of ...here is quite long. Is this bad? And the same question is about what is afterishere or in my main question. It has been marked there aslong complementat the end of sentence. – user2626 May 19 '18 at 12:37