IMHO science is a necessity, and the arts are a luxury. I suppose it depends on how you define science, but if you think of it as knowing how nature works and using the knowledge to your advantage, then even the most basic things fall into the category of science. For example even when man lived in caves and hunted, surely knowing how to make spears, use fire etc all show an understanding of nature i.e. friction produces heat which causes wood to burn, knowing that flint can be easily split and formed into a spearhead etc. If that can be classed as science, then without it very little advancement would be possible.
Alternatively think of it like this: If some of the greatest scientists/artist had not existed, how would that affect our day to day lives? If Shakespeare had not existed the world would be short of 37 plays, but how many people's lives would this affect and by how much? If Faraday had not existed we would not know how to generate electricity. There would be no cars, no fridges, no electronic communication. So the absence of a single discovery makes us unable to travel any faster than on horseback, unable to store food and unable to communicate apart from via a messenger or in person. These are all things which would affect a lot of people in a significant way.
I have nothing against the arts, I enjoy listening to music and reading etc but I think it is ridiculous to claim they are more important than the sciences. Are they more fun than the sciences? Maybe, but without science you would probably be sitting shivering in a cave (assuming you hadn't already died from an easily curable disease) - how much fun is that?