van Fraassen, Bas - Laws and Symmetry

When philosophers discuss laws of nature, they speak in terms of universality and necessity. Science too knows the terminology of laws, both in title ('Ohm's law', 'the law of conservation of energy'), and in generic classifications ('laws of motion', 'conservation laws'). Scientists, however, do not speak of law in terms of universality and necessity, but in terms of symmetry, transformations, and invariance.