The word "since" can be used to mean "because" or to indicate time. As a result of this dual meaning, confusion can occur.But Ferguson minimizes the confusion in this way:
Ordinarily, however, the context of the sentence makes it clear which meaning is intended.Here's my advice in Garbl's Editorial Style Manual:
because, since Both words can be used to mean "for the reason that." Because is the stronger conjunction for pointing out a direct cause-effect relationship: They went to the concert because they had been given tickets. Since is milder in suggesting a cause-effect relationship: Since I love folk music, I went to the concert. When readers might confuse since with its meaning "from the time that," use because.My style manual also refers to related advice in Garbl's Myths and Superstitions of Writing. Citing other writing experts, including Wilson Follett, it says:
Myth: Never use since to mean because.
"There is a groundless notion current in both the lower schools and in the world of affairs that since has an exclusive reference to time and therefore cannot be used as a casual conjunction. ... No warrant exists for avoiding this usage, which goes back, beyond Chaucer, to Anglo-Saxon. ..." -- Wilson Follett, 1966