 As we have seen, it is generally recognised that conservatism is not dogmatic reaction. It advocates piecemeal, moderate reform, which follows from its scepticism concerning reason, and its valuing of experience concerning human affairs. Burke argued that “a state without the means of some change is without the means of its conservation”. But change must be cautious, because knowledge is imperfect and consequences can be unintended. According to conservatives, institutions and morals evolve, their weaknesses become apparent and obvious political abuses are corrected; but ancient institutions embody a tacit wisdom that deserves respect. Conservatives are sceptical of large-scale constitutional, economic or cultural planning, because behaviour and institutions have evolved through the wisdom of generations, which cannot easily be articulated.