In Romeo and Juliet, what does Lord Capulet's decree show about his attitude to Juliet?

In Act III, scene v, Lord Capulet plans to cheer Juliet
up, whom he imagines is grieving over the loss of her cousin Tybalt, by announcing her
engagement to Paris.  He treats her as if she were a small child who has fallen and
skinned her knee and can be appeased with a piece of
candy.

Though he enters the scene trying to lighten
Juliet's mood, his own mood darkens considerably when she doesn't respond with claps and
kisses to his offer of marriage to Paris.  Juliet
says:

Proud
can I never be of what I hate,

But thankful even for hate
that is meant love.

These
lines basically mean "thanks, but no thanks" -- to which Capulet explodes.  There is no
clear direction of the action here, but Lady Capulet does say, "What, are you mad?" and
Capulet says, "My fingers itch," both indicating the possibility of violence inflicted
on Juliet by Capulet.

Whether there is actual physical
violence in the scene or not, Capulet does give Juliet an ultimatum:  Either marry
Paris, or leave his home.  The second choice is one that Capulet understands the
consequences of very well.  He says, just before he exits the scene, "Beg!  Starve!  Die
in the streets!"  One, if not all, would probably be the outcome if Juliet were thrown
out of her home with no place to go.

However, all that
said, it is hard to say exactly what this says about his attitude towards Juliet. 
Shakespeare was a very aware playwright.  He shows Capulet to be very volatile, but also
very caring.  Capulet does not like to be crossed (as the exchange with Tybalt at his
party in Act I shows), but he can switch emotional gears very quickly.  When Juliet is
found "dead" in Act IV, Capulet is quite movingly
grief-stricken.

The one thing for sure, I would say, that
Capulet's decree shows, is a proud nature that dislikes being crossed by anyone,
especially his family.  He is a very astute rendering by Shakespeare of a father who
loves his child dearly, but is also capable of a very boorish paternal authority.  We
can still, today, recognize this sort of father in our modern
society.

For more information on the two sides of Capulet's
nature, please follow the character analysis link below.