I think I understand the general concept of deixis but I can't understand how it relates to the simple past and perfect tenses.
He arrived eventually is simple past and is deictic but
He has arrived at last is present perfect, and not deictic apparently.
I've consulted both A Comprehensive Grammar of the English Language and the Cambridge Grammar of the English language and I'm still none the wiser.
Can anyone please explain how the first sentence is deictic but the second one isn't?