“(Political) Freedom is the right to do whatever the laws permit.” This is a famous sentence of Montesquieu. Today we tend to describe philosophies of freedom with “positive freedom” and “negative freedom”, I think Montesquieu by this sentence fits well into the category of philosophers who advocated for negative freedom. However, he also says: ' Now a government is like everything else: to preserve it we must love it.' Does this implies that he also stands for positive freedom, because he asks people to love government? If so, is his theory about freedom self-defeating?
Negative and positive freedom
Negative freedom is largely, as you suggest, exemption from external interference in the way of coercion, constraint or force. (I could analyse and distinguish these concepts but their intuitive sense is plain enough for purposes here.) If you lock me in a room, tie me up, make dire and realistic threats which you have every intention and ability to carry out unless I comply with your wishes, then you restrict my negative freedom.
Positive freedom centres on internal factors. If, for instance, I have compulsive desires, overwhelming depression, or am neurotically indecisive, I still have negative freedom - I am not subject to external interference - but I lack the autonomy, the self-mastery, to act as a coherent agent.
Negative and positive freedom are not to be equated (as they so often confusedly are) with 'freedom from/ freedom to'. Wherever that distinction comes from it does not capture at all the difference)s) between the two freedoms, negative and positive. Nor does positive freedom involve following the mandates of the 'rational self' as Isaiah Berlin suggests. It just means the absence of a range of internal impediments to coherent action.
Now a government is like everything else: to preserve it we must love it. (Montesquieu, The Spirit of the Laws', IV.5)
Montesquieu is talking specifically of 'republican government', something at least close to democracy. The following extract from Christopher Wolfe elaborates the point about 'love' :
Every government requires obedience to its laws, a minimum of order which implies some limitation on "freedom." A monarch or a despot can ensure this minimum of order by force; it is less clear that a people can coerce itself. If force is needed, the republic is already corrupted. The people must voluntarily restrain themselves if the republic is to be preserved. To do this, Montesquieu thinks that they must have some sentiment or passion which leads them to do so. This passion is virtue, the love of one's fatherland. Without it, the likely result of license is anarchy, followed by despotism of some kind. (Christopher Wolfe, 'The Confederate Republic in Montesquieu', Polity, Vol. 9, No. 4 (Summer, 1977), pp. 427-445 : 431.)
....as a citizen must be "virtuous," love his country to the point of self-renunciation in order to avoid the anarchical possibilities inherent in democratic liberty (Wolfe : 435).
Much the same point is made negatively :
The citizens of modern republics, however, have been divided in their allegiance, since their love of country (their "virtue") is diluted by the pursuance of their individual interests, which sometimes conflict with the general good (for example, the development of powerful business and labor union monopolies). (Wolfe : 429.)
It is plain from this that what Montesquieu desiderates is 'virtue' in his citizens - active and enthusiastic support and a willingness at least in major matters to put the general good before individual interests.
Virtue or love of the political system may be essential to self-government but whatever the cogency or persuasiveness of Montesquieu's acclamation of love, it has so far as I can see no connection with positive freedom.
Montesquieu, The Spirit of the Laws, 1748 : https://socialsciences.mcmaster.ca/econ/ugcm/3ll3/montesquieu/spiritoflaws.pdf
Christopher Wolfe, 'The Confederate Republic in Montesquieu', Polity, Vol. 9, No. 4 (Summer, 1977), pp. 427-445.
Isaiah Berlin, Four Essays on Liberty, ISBN 10: 0192810340 / ISBN 13: 9780192810342 Published by Oxford Paperbacks, 1969 (reprinted many times).
Geoffrey Thomas, An Introduction to Political Philosophy, ISBN 10: 0715626442 / ISBN 13: 9780715626443 Published by Gerald Duckworth & Co Ltd, 2000 - see index under 'freedom' for negative/ positive distinction.