Its never possible to love without reasons.
That's the nature of humanity.Nothing can be done without a reason except i you are a robot.
There are two type of love
The Emotional love(Love from your heart or soul)
The spiritual love(Gods love which is unconditional or Love from the spirit)
The Emotional love is the between hus and and wife,two lovers.That emotional love is not possible without reason because that's how we are created.
The spiritual love which is unconditional is only possible by the spirit of God.
I totally agree with this your comment @iyiade in human nature before one can love there must be an attraction and what ever that attraction is , 'That is the reason ' for the love.