Humanism. It has a long and complex history, but let me define it for the sake of discussion as the attempt to replace "humanity" with God, the worship of man, a form of idolatry. The biblical event that symbolizes the aspirations of humanism the best is the episode or the Tower of Babel, where God had to divide people into nations by confusing their speech because they had gathered into one humanity to build a tower to heaven, in defiance of God . . . much like today.

The love of humanity. It sounds so nice. People might even say that it sounds Christian. Surely Christ was a great lover or humanity, wasn't he?
I think that the love of humanity is in fact very unchristian, and that a healthy contempt for humanity is vital to persevering as a Catholic. Humanism means loving fallen man, which means being complicit with the sin that is in man. Love of humanity is a kind of mushy sentimentality, a softness of the heart, being kind, "humane" . . . this is not the fire of charity in the saints.

 I don't think Christ was a lover of humanity. He wasn't kind to man, He was extremely demanding. He wasn't a kind man that made people "feel better". Every false prophet, every false shepherd, uses the tactic of making people "feel better" with soothing words. But Christ came not to bring that false peace that the world seeks, but a sword.

You will never be able to convert souls if you "love people for who they are" (a phrase humanists today love to use today to indicate the peak of virtue). You have to see the potential Christ and potential Mary in every man and woman, and the part in them that is still Adam or Eve you have to thoroughly despise. Say you meet a nice old lady. She's nice, she's friendly, but she isn't a believer, and her sweet kindness is not charity. So is it truly charitable of you to be nice and kind to the old lady in return and neglect to mention that she is in fact a sinner? Of course not, because then you give her the false impression that her kindness is enough to redeem her, when it isn't. Human kindness is not Christian love. Human kindness is just another form of worldliness, and in a way a more deceptive form because it appears goodly.

One of the key messages of the New Testament is that in order to follow Christ you have to despise yourself, and in order to find God you have to despise the world. Without this healthy hatred of sin we fall into complacency, into worldliness. We tell ourselves it's OK if we aren't good Christians because at least we're "good people" (we smile at others and apologize when we bump into someone). If we love humanity, we feel less in need of God. If we love humanity, we don't need to repent for our sins, because to sin is only "to be human".

I think you find a contempt for humanity in the saints. It's part of what made them so strong - they didn't have any "human respect" to prevent them from preaching the truth out of fear of offending men.

Let me take an example from the ancient pagan world. Contrast the philosopher Plato with the cynic Diogenes. Plato was a humanist, he talked about love and ideals and perfecting humanity through philosophy; then you have Diogenes who lived with dogs and the street and according to legend pulled off stunts like going through the city with a lamp during the day and saying, "don't mind me, I'm just looking for an honest man", and telling Alexander the Great that he couldn't tell the difference between his father's bones and anybody else's. Which do you think is closer to the saints? Which do you think would have been quicker to accept Christ's gospel?

There's a quote from Dostoevsky. One of his characters says that the more he loves humanity in the abstract the more unbearable he finds his actual neighbours, how little he can put up with them. This is the contrast between Christianity and Humanism - the Christians hate humanity and love their neighbour, the Humanists love humanity but despise their neighbour.

Sorry for rambling. I'd like to hear your thoughts. Perhaps people will accuse me of over-emphasizing grace at the expense of nature, that grace builds on nature, that natural kindness is good and that charity only builds on and perfect it. To an extent this may be true, but I want to distinguish between a heartfelt kindness that is actually very rare and that very common worldly kindness which is in fact only a way of "getting on" with others -  a disguised form of selfishness.

Humanism is a fundamental part of the anti-Christ ʝʊdɛօ - masonic agenda. Replace love of God by love of neighboris one of its maneuvers. It camouflages under "nice" ideas to make people forget about Christ, to swift priorities from what is truly divine. This has happened in all level of society, including, unfortunately, within the Church hierarchy herself. Basically, it promotes what is called is an "horizontal religion", whose objective is man, instead of "vertical religion" whose primary object is God. It means loving and serving man, while disregarding God. The pantheistic philanthropic pursues of the modern Church is another example of this. It is really a godless, naturalistic, and ultimately luciferian philanthropy though, which focuses on "social service", help for the poor, diverse communities, etc. and other leftists communist ideals.  

This is clearly against the first commandment.  YOU SHALL LOVE THE LORD YOUR GOD WITH ALL YOUR HEART, AND WITH ALL YOUR SOUL, AND WITH ALL YOUR MIND.

Humanism runs opposite to the first commandment and therefore is a very serious matter.  Must be resisted.