Gothic love is a subculture which touches on many things beyond music and fashion, though those are the most readily identifiable aspects of it. It's hard to put the finger on any set ethic or philosophy to the gothic scene, as gothic people are generally love many different things (some aren't even interested in the music or fashion at all). My own take on it is that one common aspect of the gothic scene is a desire to step outside the mundane everyday humdrum and find something a bit different and more exciting. This can be through fashion, music, artistic/poetic leanings, alternative religions/philosophies and various other interests and subjects generally associated with a somewhat bohemian image. None of these things is universal, or compulsory.
'Beauty in Darkness' is my favorite term for this gothic aesthetic, which can take the form of funereal fashion styles, haunting, weird or gloomy music, and tastes for anything from Romantic Poets to b-grade horror movies. It's an intellectual, bohemian subculture with a dark, morbid aesthetic that people can take or leave aspects of as they please.
Gothic is a lifestyle in the truest sense of the word. What I mean is that it is not just putting on a black dress, dying your hair, and applying black makeup and going out to the clubs for an evening of thrashing wildly to music. Rather, although this is an enjoyable by-product of such, it is much deeper than this.
The gothic lifestyle is the romance of the night as it calls to your very soul. Seeing in the darkness the beauty that is missed beneath the sunlight, when others retire to their beds. The way the moonlight plays along the trees, the deep gray of the fog, the keening of animals that sleep away the day. All of this plays a significant part of the lifestyle as a whole. It is seeing the beauty in what others shun. Oftentimes, people equate the night and darkness in general as 'evil', due to hundred-thousand year old stereotypes and stories. To me, it is ethereal and other-worldly, one-half of our very existence, and something to be embraced as just as significant to our understanding of the world and our place within it as the daylight hours.