I recently engaged in a rather fruitless discussion online concerning the question of whether Samuel Coleridge could properly be considered a 'conservative' thinker or not. My discussion partner seemed to be eager to classify the poet as a conservative and I expressed my belief that Coleridge's politics are considerably more ambiguous than to allow simple classification. I cannot rehash the entire conversation here but it made be think about the difficult question of classifying certain thinkers as either 'conservative' or 'radical,' particularly in the days before the Victorian era.
In the days after Karl Marx and the beginning of the Communist movement, politics became somewhat more clarified and thinkers easier to classify. However, even in those days of apparent clarity, things are not always cut and dry. I think, for example, that a pretty strong argument can be made that many in the orthodox communist movement were never really radical. I have read many such arguments by activists and academics alike who contend that the Communist movement was just a flip-side of capitalism, if you will, and that the Soviet Union was simply a form of so-called command capitalism, etc. As well as post-modern arguments by such thinkers as Derrida and Baudrillard.
Of course any such arguments are contingent on the question of what we actually think of as 'radical' and what we thing of as 'conservative.' I have long thought that one interesting why of looking at the question was encapsulated in the argument between Marx and Hegel concerning the Philosophy of Right. In the context of this discourse, radical and conservative ideologies are separated, I believe, by the degree of legitimacy of the state. A conservative before the 'democratic' era believed that the apparatus of the state, in whatever particular form it took, was the expression of the general good. In the 'democratic' ear, conservatives generally believe that the state (or government) is the expression of the 'general will.' Things are not that simple, of course, because conservatives will resist the 'general will' if it doesn't express the conservative goals.
Now on the other hand, radical ideology is expressed by the assumption that the state (whatever form it takes) is generally an expression of the ruling, or capitalist, class.(As Marx famously said; the ruling ideology is the ideology of the ruling) While various factors have allowed the state, to gradually and to varying degrees, to be open and even to contain important social elements, the radial believes that there is a constant and uphill battle to keep excessive power out of the hands of those who want to create a system that simply serves the moneyed interests. Thus radicals in the modern era generally look to ensure ever greater levels of equality of opportunity and empowerment for those who lack the opportunities and even the inherent abilities to compete with those with greater power and more opportunity. Radicals, simply put, don't believe that the so-called 'market' will ensure greater levels of equality and opportunity. In fact, quiet the opposite. Radicals believe that the rich and powerful are constantly attempting to undermine the possibilities for equality, economic or otherwise.
This is, of course, an extremely truncated argument, but I think it captures the essence of what is really at stake. You could write a whole book just to clarify this argument and answer the various objections which people will put forward. And people can disagree with various parts of this analysis, but my point was really to introduce the other part of the argument.
Having said all of this, the argument that I was having online was more complicated because it concerned thinkers in the pre-marxist, pre-communist, and even pre-capitalist (in the full sense of the word), eras. Thinkers like Thomas Paine generally were suspicious of the state in general because they had never seen it as anything but the plaything of the aristocracy. Late 18th and early 19th century radicals could not have imagined the degree of democracy that later generations achieved and the degree to which the state could be a force of good for social welfare even while still largely in the hands of the rich and powerful. Furthermore, radicals and conservatives alike were struggling with the troubling events in the aftermath of the French Revolution. Men like Thomas Jefferson is often considered a genuine radical but he still supported slavery, and voting rights exclusively for a small, land-owning class.
The conservatives of this era were generally a little easier to pin down because many of them, like Edmund Burke, reacted to the French Revolution with a very simplistic argument that defended the ancient regime and the rule of the aristocracy and in many cases said point blank that the 'people' couldn't be trusted and the King and his ilk needed to guide society for its own good. Many modern conservatives actually believe the same thing only with the "market" replacing the King as an abstract sovereign and the corporations replacing the aristocracy as de facto rulers. For these people democracy is limited by the fact that it must only elect groups to 'administer' the market. If the people try to make decisions that contravene the fundamentals of the market, they will be very quick to condemn democracy.
But men like Coleridge were much harder to classify. He profoundly distrusted the aristocracy, he condemned the growing inequities and abuses of capitalism, and he spoke in favor of much greater degrees of economic and social equalities. In the early years Coleridge was clearly a Jacobin and was a radical in the same way that men like Hazlitt and Godwin were (only with a strong Christian streak guiding his morals). But Coleridge, even before the Revolution took a frightening turn, was something of a gradualist who was very wary of revolutions and thought that change should come through slow moral development of the people. But William Godwin also believed this and he is often considered the consummate radical of the late 18th century. Coleridge gradually came to believe that for society to move forward it had to be guided by institutions that encapsulated the moral and ethical good. This sounds like a fairly conservative idea, however, there are many on the left such as Christian Socialists, who also believe this. I think that even with his later, more conservative writings in mind, Coleridge is never an easy thinker to classify and that if he were alive today and saw the degree to which the state has promoted, at various times and in various ways, social and economic equality, Coleridge would be fairly radical by today's standards. I think he would distrust corporate power today in the same way that he distrusted reactionary Toryism in his own day.
The problems of radicalism and conservatism are always made more difficult by the shifting ground of power and state. But in the end I think radicalism is always defined by a desire to increase social and economic equality - not for the sake of homogeneity but for the exact opposite - so that society can benefit from the dynamic elements of difference in society.