Nothing reminds me more than Fitzgerald's "The Great Gatsby" of the deception that loving a woman is enough. That is the great weakness of all men.
Men are loyal to that idea more than to most things, even themselves. And this is good for a marriage.
Men and woman share a few basic instincts when it comes to coupling. First, the need to reproduce and the need to nurture/protect. Over and above that, instincts vary.
I think it's of men's instincts, to love first, then make love and then to protect. But a woman's are first to be protected, then to have children and then nurture them. Love is not essential for a woman, it's useful. Reproduction is a shared goal and leading up to and beyond that, it seems to fit well with both genders basic instincts.
But why does a man even want to protect a woman. The answer to this question is Love. A man protects a woman because he has come to love her, appreciate her, admire her just like a man who makes a crude hunting knife comes to appreciate it, as it serves him well over time or can see the benefit in its purpose and construction. He protects and cares this for it. He becomes to love the knife.
For instance, it's a mans instinct, I think to protect while it's a woman's instinct to nurture. Thus protection while raising nurturing and raising children is desirable for a woman. Less so for a man. When a man loves a woman, this is great for a woman. Then again, I am a man and am I too subjective? Perhaps.
But a man's Achilles heel is that he becomes to love her. Without love, it doesn't affect him if he does or doesn't protect her. Yet it's important for a woman. A woman's needs not a man for his love, but for his protection but a mans love can ensure this. His love is useful to a woman or it's not. If not it can be caste away. This is what a man must deal with. Not a woman. This is the essence of our instincts, I think and love is just an auxiliary force that binds men to woman. A woman love is very much an after thought. A woman's love is driven by admiration of her partner, loyalty etc... This ultimately holds a relationship together.
Sure, other instincts lead off from these two base instincts(protection & nurturing) but have less to do with establishing a relationship between a man and a woman and more to do with life and living which is not what I'm talking about here(like the new to eat)
To love is to protect.
So it's not enough for a man to love a woman, for a woman to bare his children. This is the romantic fallacy that plague the great men of the world. It will continue to plague them in the future as it has done in the past to considerable detriment of men. It's too bad, but it's not catastrophic - it's the way it always has been.
One of the side effects, I believe of this protection/nurture man/woman bond is that of love, trust loyalty, admiration etc. mentioned above, all which make the bond that much stronger.
I like the great Gatsby because of this. I had thought I might title this "The volatility of woman" but thought better of it.