I have seen this mistaken view expressed a few times, including on blogs. The blogger presents evidence that the Church’s teaching is being openly rejected, and that the clergy or hierarchy seemingly do nothing to correct the dissent. A commenter says: “Why do you want to exclude your fellow-Catholics who think differently from you? Surely the Church should welcome all views. After all, the word Catholic means inclusive.”
And the answer is, No it doesn’t: not in the Church's sense of the word. Certainly this is one of the meanings given to the word in an ordinary dictionary. But the Church's meaning is more precise, as I’m sure my readers know, being defined as universal.
The English Penny Catechism can’t be beaten for brevity:
The Church is Catholic or universal because she subsists in all ages, teaches all nations, and is the one ark of salvation for all.The Catholic Encyclopedia gives an interesting and detailed account of the origins of the word Catholic as applied to the Church. In whatever context the term is used, it is clear that the Catholicity, the world-wide reach of the Catholic Church, is inseparable from Her true teaching. You will see what I mean if you read the whole article.
The Encyclopedia was published in 1917, a few years after the death of Pope St Pius X, who had issued detailed warnings against Modernism, described as the synthesis of all heresies. Bearing this date in mind, it is fascinating to read its dismissal of the idea that the Church can find room both for true teachings and their rejection. Here is the relevant passage, to which I have added a few paragraph breaks for ease of reading.
"It should be said that among some confused thinkers of the Anglican communion, as also among certain representatives of Modernist opinions, an interpretation of the Catholicity of the Church has lately come into fashion which has little connection with anything that has hitherto fallen under our notice. Starting with the conception familiar in such locutions as "a man of catholic tastes", meaning a man who excludes no rational interest from his sympathies, these writers would persuade us that a catholic church either does or should mean a church endowed with unlimited comprehensiveness, i.e. which is prepared to welcome and assimilate all opinions honestly held, however contradictory.
"To this it may be answered that the idea is absolutely foreign to the connotation of the phrase Catholic Church as we can trace it in the writings of the Fathers. To take a term consecrated by centuries of usage and to attach a brand-new meaning to it, of which those who through the ages had it constantly on their lips never dreamed, is to say the least extremely misleading.
"If this comprehensiveness and elasticity of belief is regarded as a desirable quality, by all means let it have a new name of its own, but it is dishonest to leave the impression upon the ignorant or the credulous, that this is the idea which devout men in past ages have all along been groping for, and that it has been left to the religious thinkers of our own day to evolve from the name catholic its true and real significance.
"So far from the idea of a nebulous and absorbent substance imperceptibly shading off into the media which surround it, the conception of the Fathers was that the Catholic Church was cut off by the most clearly defined of lines from all that lay outside. Its primary function, we might also say, was to set itself in acute opposition to all that threatened its vital principle of unity and stability.
"It is true that patristic writers may sometimes play with the word catholic, and develop its etymological suggestiveness with an eye to erudition or edification, but the only connotation upon which they insist as a matter of serious import is the idea of diffusion throughout the world."