The phrase, a decent respect for the opinions of mankind, was intended to convey a respect for what mankind thinks. Opinions are biases indulged by mankind inside their thought-matrices. Mankind is the species known as Homo Sapiens Sapiens.
Answer:
I believe this question is based on the poem by Emily Dickinson;
There is no frigate like a book
To take us lands away,
Nor any coursers like a page
Of prancing poetry.
This traverse may the poorest take
Without oppress of toll;
How frugal is the chariot
That bears a human soul!
From this poem, the similarity i can find between a book and a frigate, a courser, and a chariot is their ability to take an individual to a different place physically or mentally. For effect, the book can take an individual to another place mentally, while the frigate, courser and chariot will take an individual to another place physically.